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Revision 1.171, Wed Feb 11 06:30:21 2009 UTC (15 years, 3 months ago) by noro
Branch: MAIN
Changes since 1.170: +3 -3 lines

Fixed a bug in ndv_check_membership.

/* $OpenXM: OpenXM_contrib2/asir2000/engine/nd.c,v 1.171 2009/02/11 06:30:21 noro Exp $ */

#include "nd.h"

int diag_period = 6;
int (*ndl_compare_function)(UINT *a1,UINT *a2);
int nd_dcomp;
NM _nm_free_list;
ND _nd_free_list;
ND_pairs _ndp_free_list;
NODE nd_hcf;

static NODE nd_subst;
static VL nd_vc;
static int nd_ntrans;
static int nd_nalg;
#if 0
static int ndv_alloc;
#endif
#if 1
static int nd_f4_nsp=0x7fffffff;
#else
static int nd_f4_nsp=50;
#endif
static double nd_scale=2;
static UINT **nd_bound;
static struct order_spec *nd_ord;
static EPOS nd_epos;
static BlockMask nd_blockmask;
static int nd_nvar;
static int nd_isrlex;
static int nd_epw,nd_bpe,nd_wpd,nd_exporigin;
static UINT nd_mask[32];
static UINT nd_mask0,nd_mask1;

static NDV *nd_ps;
static NDV *nd_ps_trace;
static RHist *nd_psh;
static int nd_psn,nd_pslen;
static RHist *nd_red;
static int *nd_work_vector;
static int **nd_matrix;
static int nd_matrix_len;
static struct weight_or_block *nd_worb;
static int nd_worb_len;
static int nd_found,nd_create,nd_notfirst;
static int nmv_adv;
static int nd_demand;
static int nd_module,nd_ispot,nd_mpos;
static NODE nd_tracelist;
static NODE nd_alltracelist;

NumberField get_numberfield();
UINT *nd_det_compute_bound(NDV **dm,int n,int j);
void nd_det_reconstruct(NDV **dm,int n,int j,NDV d);
void nd_heu_nezgcdnpz(VL vl,P *pl,int m,int full,P *pr);
int nd_monic(int m,ND *p);
NDV plain_vect_to_ndv_q(Q *mat,int col,UINT *s0vect);
LIST ndvtopl(int mod,VL vl,VL dvl,NDV p,int rank);
NDV pltondv(VL vl,VL dvl,LIST p);
void pltozpl(LIST l,Q *cont,LIST *pp);
void ndl_max(UINT *d1,unsigned *d2,UINT *d);
pointer GC_malloc_atomic_ignore_off_page(int);
void nmtodp(int mod,NM m,DP *r);
NODE reverse_node(NODE n);
P ndc_div(int mod,union oNDC a,union oNDC b);
P ndctop(int mod,union oNDC c);
void finalize_tracelist(int i,P cont);
void conv_ilist(int demand,int trace,NODE g,int **indp);

extern int Denominator,DP_Multiple;

void nd_free_private_storage()
{
    _nm_free_list = 0;
    _ndp_free_list = 0;
#if 0
    GC_gcollect();
#endif
}

void _NM_alloc()
{
    NM p;
    int i;

    for ( i = 0; i < 1024; i++ ) {
        p = (NM)GC_malloc(sizeof(struct oNM)+(nd_wpd-1)*sizeof(UINT));
        p->next = _nm_free_list; _nm_free_list = p;
    }
}

void _ND_alloc()
{
    ND p;
    int i;

    for ( i = 0; i < 1024; i++ ) {
        p = (ND)GC_malloc(sizeof(struct oND));
        p->body = (NM)_nd_free_list; _nd_free_list = p;
    }
}

void _NDP_alloc()
{
    ND_pairs p;
    int i;

    for ( i = 0; i < 1024; i++ ) {
        p = (ND_pairs)GC_malloc(sizeof(struct oND_pairs)
            +(nd_wpd-1)*sizeof(UINT));
        p->next = _ndp_free_list; _ndp_free_list = p;
    }
}

INLINE int nd_length(ND p)
{
    NM m;
    int i;

    if ( !p )
        return 0;
    else {
        for ( i = 0, m = BDY(p); m; m = NEXT(m), i++ );
        return i;
    }
}

INLINE int ndl_reducible(UINT *d1,UINT *d2)
{
    UINT u1,u2;
    int i,j;

    if ( nd_module && (MPOS(d1) != MPOS(d2)) ) return 0;

    if ( TD(d1) < TD(d2) ) return 0;
#if USE_UNROLL
    switch ( nd_bpe ) {
        case 3:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                if ( (u1&0x38000000) < (u2&0x38000000) ) return 0;
                if ( (u1& 0x7000000) < (u2& 0x7000000) ) return 0;
                if ( (u1&  0xe00000) < (u2&  0xe00000) ) return 0;
                if ( (u1&  0x1c0000) < (u2&  0x1c0000) ) return 0;
                if ( (u1&   0x38000) < (u2&   0x38000) ) return 0;
                if ( (u1&    0x7000) < (u2&    0x7000) ) return 0;
                if ( (u1&     0xe00) < (u2&     0xe00) ) return 0;
                if ( (u1&     0x1c0) < (u2&     0x1c0) ) return 0;
                if ( (u1&      0x38) < (u2&      0x38) ) return 0;
                if ( (u1&       0x7) < (u2&       0x7) ) return 0;
            }
            return 1;
            break;
        case 4:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                if ( (u1&0xf0000000) < (u2&0xf0000000) ) return 0;
                if ( (u1& 0xf000000) < (u2& 0xf000000) ) return 0;
                if ( (u1&  0xf00000) < (u2&  0xf00000) ) return 0;
                if ( (u1&   0xf0000) < (u2&   0xf0000) ) return 0;
                if ( (u1&    0xf000) < (u2&    0xf000) ) return 0;
                if ( (u1&     0xf00) < (u2&     0xf00) ) return 0;
                if ( (u1&      0xf0) < (u2&      0xf0) ) return 0;
                if ( (u1&       0xf) < (u2&       0xf) ) return 0;
            }
            return 1;
            break;
        case 6:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                if ( (u1&0x3f000000) < (u2&0x3f000000) ) return 0;
                if ( (u1&  0xfc0000) < (u2&  0xfc0000) ) return 0;
                if ( (u1&   0x3f000) < (u2&   0x3f000) ) return 0;
                if ( (u1&     0xfc0) < (u2&     0xfc0) ) return 0;
                if ( (u1&      0x3f) < (u2&      0x3f) ) return 0;
            }
            return 1;
            break;
        case 8:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                if ( (u1&0xff000000) < (u2&0xff000000) ) return 0;
                if ( (u1&  0xff0000) < (u2&  0xff0000) ) return 0;
                if ( (u1&    0xff00) < (u2&    0xff00) ) return 0;
                if ( (u1&      0xff) < (u2&      0xff) ) return 0;
            }
            return 1;
            break;
        case 16:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                if ( (u1&0xffff0000) < (u2&0xffff0000) ) return 0;
                if ( (u1&    0xffff) < (u2&    0xffff) ) return 0;
            }
            return 1;
            break;
        case 32:
            for ( i = nd_exporigin; i < nd_wpd; i++ )
                if ( d1[i] < d2[i] ) return 0;
            return 1;
            break;
        default:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                for ( j = 0; j < nd_epw; j++ )
                    if ( (u1&nd_mask[j]) < (u2&nd_mask[j]) ) return 0;
            }
            return 1;
    }
#else
    for ( i = nd_exporigin; i < nd_wpd; i++ ) {
        u1 = d1[i]; u2 = d2[i];
        for ( j = 0; j < nd_epw; j++ )
            if ( (u1&nd_mask[j]) < (u2&nd_mask[j]) ) return 0;
    }
    return 1;
#endif
}

/*
 * If the current order is a block order,
 * then the last block is length 1 and contains
 * the homo variable. Otherwise, the original
 * order is either 0 or 2.
 */

void ndl_homogenize(UINT *d,UINT *r,int obpe,EPOS oepos,int ompos,int weight)
{
    int w,i,e,n,omask0;

    omask0 = obpe==32?0xffffffff:((1<<obpe)-1);
    n = nd_nvar-1;
    ndl_zero(r);
    for ( i = 0; i < n; i++ ) {
        e = GET_EXP_OLD(d,i);
        PUT_EXP(r,i,e);
    }
    w = TD(d);
    PUT_EXP(r,nd_nvar-1,weight-w);
    if ( nd_module ) MPOS(r) = d[ompos];
    TD(r) = weight;
    if ( nd_blockmask ) ndl_weight_mask(r);
}

void ndl_dehomogenize(UINT *d)
{
    UINT mask;
    UINT h;
    int i,bits;

    if ( nd_blockmask ) {
        h = GET_EXP(d,nd_nvar-1);
        XOR_EXP(d,nd_nvar-1,h);
        TD(d) -= h;
        ndl_weight_mask(d);
    } else {
        if ( nd_isrlex ) {
            if ( nd_bpe == 32 ) {
                h = d[nd_exporigin];
                for ( i = nd_exporigin+1; i < nd_wpd; i++ )
                    d[i-1] = d[i];
                d[i-1] = 0;
                TD(d) -= h;
            } else {
                bits = nd_epw*nd_bpe;
                mask = bits==32?0xffffffff:((1<<(nd_epw*nd_bpe))-1);
                h = (d[nd_exporigin]>>((nd_epw-1)*nd_bpe))&nd_mask0;
                for ( i = nd_exporigin; i < nd_wpd; i++ )
                    d[i] = ((d[i]<<nd_bpe)&mask)
                        |(i+1<nd_wpd?((d[i+1]>>((nd_epw-1)*nd_bpe))&nd_mask0):0);
                TD(d) -= h;
            }
        } else {
            h = GET_EXP(d,nd_nvar-1);
            XOR_EXP(d,nd_nvar-1,h);
            TD(d) -= h;
        }
    }
}

void ndl_lcm(UINT *d1,unsigned *d2,UINT *d)
{
    UINT t1,t2,u,u1,u2;
    int i,j,l;

    if ( nd_module && (MPOS(d1) != MPOS(d2)) )
        error("ndl_lcm : inconsistent monomials");
#if USE_UNROLL
    switch ( nd_bpe ) {
        case 3:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                t1 = (u1&0x38000000); t2 = (u2&0x38000000); u = t1>t2?t1:t2;
                t1 = (u1& 0x7000000); t2 = (u2& 0x7000000); u |= t1>t2?t1:t2;
                t1 = (u1&  0xe00000); t2 = (u2&  0xe00000); u |= t1>t2?t1:t2;
                t1 = (u1&  0x1c0000); t2 = (u2&  0x1c0000); u |= t1>t2?t1:t2;
                t1 = (u1&   0x38000); t2 = (u2&   0x38000); u |= t1>t2?t1:t2;
                t1 = (u1&    0x7000); t2 = (u2&    0x7000); u |= t1>t2?t1:t2;
                t1 = (u1&     0xe00); t2 = (u2&     0xe00); u |= t1>t2?t1:t2;
                t1 = (u1&     0x1c0); t2 = (u2&     0x1c0); u |= t1>t2?t1:t2;
                t1 = (u1&      0x38); t2 = (u2&      0x38); u |= t1>t2?t1:t2;
                t1 = (u1&       0x7); t2 = (u2&       0x7); u |= t1>t2?t1:t2;
                d[i] = u;
            }
            break;
        case 4:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                t1 = (u1&0xf0000000); t2 = (u2&0xf0000000); u = t1>t2?t1:t2;
                t1 = (u1& 0xf000000); t2 = (u2& 0xf000000); u |= t1>t2?t1:t2;
                t1 = (u1&  0xf00000); t2 = (u2&  0xf00000); u |= t1>t2?t1:t2;
                t1 = (u1&   0xf0000); t2 = (u2&   0xf0000); u |= t1>t2?t1:t2;
                t1 = (u1&    0xf000); t2 = (u2&    0xf000); u |= t1>t2?t1:t2;
                t1 = (u1&     0xf00); t2 = (u2&     0xf00); u |= t1>t2?t1:t2;
                t1 = (u1&      0xf0); t2 = (u2&      0xf0); u |= t1>t2?t1:t2;
                t1 = (u1&       0xf); t2 = (u2&       0xf); u |= t1>t2?t1:t2;
                d[i] = u;
            }
            break;
        case 6:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                t1 = (u1&0x3f000000); t2 = (u2&0x3f000000); u = t1>t2?t1:t2;
                t1 = (u1&  0xfc0000); t2 = (u2&  0xfc0000); u |= t1>t2?t1:t2;
                t1 = (u1&   0x3f000); t2 = (u2&   0x3f000); u |= t1>t2?t1:t2;
                t1 = (u1&     0xfc0); t2 = (u2&     0xfc0); u |= t1>t2?t1:t2;
                t1 = (u1&      0x3f); t2 = (u2&      0x3f); u |= t1>t2?t1:t2;
                d[i] = u;
            }
            break;
        case 8:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                t1 = (u1&0xff000000); t2 = (u2&0xff000000); u = t1>t2?t1:t2;
                t1 = (u1&  0xff0000); t2 = (u2&  0xff0000); u |= t1>t2?t1:t2;
                t1 = (u1&    0xff00); t2 = (u2&    0xff00); u |= t1>t2?t1:t2;
                t1 = (u1&      0xff); t2 = (u2&      0xff); u |= t1>t2?t1:t2;
                d[i] = u;
            }
            break;
        case 16:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                t1 = (u1&0xffff0000); t2 = (u2&0xffff0000); u = t1>t2?t1:t2;
                t1 = (u1&    0xffff); t2 = (u2&    0xffff); u |= t1>t2?t1:t2;
                d[i] = u;
            }
            break;
        case 32:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i]; 
                d[i] = u1>u2?u1:u2;
            }
            break;
        default:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i]; 
                for ( j = 0, u = 0; j < nd_epw; j++ ) {
                    t1 = (u1&nd_mask[j]); t2 = (u2&nd_mask[j]); u |= t1>t2?t1:t2;
                }
                d[i] = u;
            }
            break;
    }
#else
    for ( i = nd_exporigin; i < nd_wpd; i++ ) {
        u1 = d1[i]; u2 = d2[i]; 
        for ( j = 0, u = 0; j < nd_epw; j++ ) {
            t1 = (u1&nd_mask[j]); t2 = (u2&nd_mask[j]); u |= t1>t2?t1:t2;
        }
        d[i] = u;
    }
#endif
    if ( nd_module ) MPOS(d) = MPOS(d1);
    TD(d) = ndl_weight(d);
    if ( nd_blockmask ) ndl_weight_mask(d);
}

void ndl_max(UINT *d1,unsigned *d2,UINT *d)
{
    UINT t1,t2,u,u1,u2;
    int i,j,l;

    for ( i = nd_exporigin; i < nd_wpd; i++ ) {
        u1 = d1[i]; u2 = d2[i]; 
        for ( j = 0, u = 0; j < nd_epw; j++ ) {
            t1 = (u1&nd_mask[j]); t2 = (u2&nd_mask[j]); u |= t1>t2?t1:t2;
        }
        d[i] = u;
    }
}

int ndl_weight(UINT *d)
{
    UINT t,u;
    int i,j;

    if ( current_dl_weight_vector )
        for ( i = 0, t = 0; i < nd_nvar; i++ ) {
            u = GET_EXP(d,i);
            t += MUL_WEIGHT(u,i);
        }
    else
        for ( t = 0, i = nd_exporigin; i < nd_wpd; i++ ) {
            u = d[i];
            for ( j = 0; j < nd_epw; j++, u>>=nd_bpe )
                t += (u&nd_mask0); 
        }
    if ( nd_module && current_module_weight_vector && MPOS(d) )
        t += current_module_weight_vector[MPOS(d)];
    return t;
}

void ndl_weight_mask(UINT *d)
{
    UINT t,u;
    UINT *mask;
    int i,j,k,l;

    l = nd_blockmask->n;
    for ( k = 0; k < l; k++ ) {
        mask = nd_blockmask->mask[k];
        if ( current_dl_weight_vector )
            for ( i = 0, t = 0; i < nd_nvar; i++ ) {
                u = GET_EXP_MASK(d,i,mask);
                t += MUL_WEIGHT(u,i);
            }
        else
            for ( t = 0, i = nd_exporigin; i < nd_wpd; i++ ) {
                u = d[i]&mask[i];
                for ( j = 0; j < nd_epw; j++, u>>=nd_bpe )
                    t += (u&nd_mask0); 
            }
        d[k+1] = t;
    }
}

int ndl_lex_compare(UINT *d1,UINT *d2)
{
    int i;

    d1 += nd_exporigin;
    d2 += nd_exporigin;
    for ( i = nd_exporigin; i < nd_wpd; i++, d1++, d2++ )
        if ( *d1 > *d2 )
            return nd_isrlex ? -1 : 1;
        else if ( *d1 < *d2 )
            return nd_isrlex ? 1 : -1;
    return 0;
}

int ndl_block_compare(UINT *d1,UINT *d2)
{
    int i,l,j,ord_o,ord_l;
    struct order_pair *op;
    UINT t1,t2,m;
    UINT *mask;

    l = nd_blockmask->n;
    op = nd_blockmask->order_pair; 
    for ( j = 0; j < l; j++ ) {
        mask = nd_blockmask->mask[j];
        ord_o = op[j].order;
        if ( ord_o < 2 )
            if ( (t1=d1[j+1]) > (t2=d2[j+1]) ) return 1;
            else if ( t1 < t2 ) return -1;
        for ( i = nd_exporigin; i < nd_wpd; i++ ) {
            m = mask[i];
            t1 = d1[i]&m;
            t2 = d2[i]&m;
            if ( t1 > t2 )
                return !ord_o ? -1 : 1;
            else if ( t1 < t2 )
                return !ord_o ? 1 : -1;
        }
    }
    return 0;
}

int ndl_matrix_compare(UINT *d1,UINT *d2)
{
    int i,j,s;
    int *v;

    for ( j = 0; j < nd_nvar; j++ )
        nd_work_vector[j] = GET_EXP(d1,j)-GET_EXP(d2,j);
    for ( i = 0; i < nd_matrix_len; i++ ) {
        v = nd_matrix[i];
        for ( j = 0, s = 0; j < nd_nvar; j++ )
            s += v[j]*nd_work_vector[j];
        if ( s > 0 ) return 1;
        else if ( s < 0 ) return -1;
    }
    return 0;
}

int ndl_composite_compare(UINT *d1,UINT *d2)
{
    int i,j,s,start,end,len,o;
    int *v;
    struct sparse_weight *sw;

    for ( j = 0; j < nd_nvar; j++ )
        nd_work_vector[j] = GET_EXP(d1,j)-GET_EXP(d2,j);
    for ( i = 0; i < nd_worb_len; i++ ) {
        len = nd_worb[i].length;
        switch ( nd_worb[i].type ) {
            case IS_DENSE_WEIGHT:
                v = nd_worb[i].body.dense_weight;
                for ( j = 0, s = 0; j < len; j++ )
                    s += v[j]*nd_work_vector[j];
                if ( s > 0 ) return 1;
                else if ( s < 0 ) return -1;
                break;
            case IS_SPARSE_WEIGHT:
                sw = nd_worb[i].body.sparse_weight;
                for ( j = 0, s = 0; j < len; j++ )
                    s += sw[j].value*nd_work_vector[sw[j].pos];
                if ( s > 0 ) return 1;
                else if ( s < 0 ) return -1;
                break;
            case IS_BLOCK:
                o = nd_worb[i].body.block.order;
                start = nd_worb[i].body.block.start;
                switch ( o ) {
                    case 0:
                        end = start+len;
                        for ( j = start, s = 0; j < end; j++ )
                            s += MUL_WEIGHT(nd_work_vector[j],j);
                        if ( s > 0 ) return 1;
                        else if ( s < 0 ) return -1;
                        for ( j = end-1; j >= start; j-- )
                            if ( nd_work_vector[j] < 0 ) return 1;
                            else if ( nd_work_vector[j] > 0 ) return -1;
                        break;
                    case 1:
                        end = start+len;
                        for ( j = start, s = 0; j < end; j++ )
                            s += MUL_WEIGHT(nd_work_vector[j],j);
                        if ( s > 0 ) return 1;
                        else if ( s < 0 ) return -1;
                        for ( j = start; j < end; j++ )
                            if ( nd_work_vector[j] > 0 ) return 1;
                            else if ( nd_work_vector[j] < 0 ) return -1;
                        break;
                    case 2:
                        for ( j = start; j < end; j++ )
                            if ( nd_work_vector[j] > 0 ) return 1;
                            else if ( nd_work_vector[j] < 0 ) return -1;
                        break;
                }
                break;
        }
    }
    return 0;
}

/* TDH -> WW -> TD-> RL */

int ndl_ww_lex_compare(UINT *d1,UINT *d2)
{
    int i,m,e1,e2;

    if ( TD(d1) > TD(d2) ) return 1;
    else if ( TD(d1) < TD(d2) ) return -1;
    m = nd_nvar>>1;
    for ( i = 0, e1 = e2 = 0; i < m; i++ ) {
        e1 += current_weyl_weight_vector[i]*(GET_EXP(d1,m+i)-GET_EXP(d1,i));
        e2 += current_weyl_weight_vector[i]*(GET_EXP(d2,m+i)-GET_EXP(d2,i));
    }
    if ( e1 > e2 ) return 1;
    else if ( e1 < e2 ) return -1;
    return ndl_lex_compare(d1,d2);
}

int ndl_module_grlex_compare(UINT *d1,UINT *d2)
{
    int i,c;

    if ( nd_ispot ) {
        if ( MPOS(d1) < MPOS(d2) ) return 1;
        else if ( MPOS(d1) > MPOS(d2) ) return -1;
    }
    if ( TD(d1) > TD(d2) ) return 1;
    else if ( TD(d1) < TD(d2) ) return -1;
    if ( c = ndl_lex_compare(d1,d2) ) return c;
    if ( !nd_ispot ) {
        if ( MPOS(d1) < MPOS(d2) ) return 1;
        else if ( MPOS(d1) > MPOS(d2) ) return -1;
    }
    return 0;
}

int ndl_module_glex_compare(UINT *d1,UINT *d2)
{
    int i,c;

    if ( nd_ispot ) {
        if ( MPOS(d1) < MPOS(d2) ) return 1;
        else if ( MPOS(d1) > MPOS(d2) ) return -1;
    }
    if ( TD(d1) > TD(d2) ) return 1;
    else if ( TD(d1) < TD(d2) ) return -1;
    if ( c = ndl_lex_compare(d1,d2) ) return c;
    if ( !nd_ispot ) {
        if ( MPOS(d1) < MPOS(d2) ) return 1;
        else if ( MPOS(d1) > MPOS(d2) ) return -1;
    }
    return 0;
}

int ndl_module_lex_compare(UINT *d1,UINT *d2)
{
    int i,c;

    if ( nd_ispot ) {
        if ( MPOS(d1) < MPOS(d2) ) return 1;
        else if ( MPOS(d1) > MPOS(d2) ) return -1;
    }
    if ( c = ndl_lex_compare(d1,d2) ) return c;
    if ( !nd_ispot ) {
        if ( MPOS(d1) < MPOS(d2) ) return 1;
        else if ( MPOS(d1) > MPOS(d2) ) return -1;
    }
    return 0;
}

int ndl_module_block_compare(UINT *d1,UINT *d2)
{
    int i,c;

    if ( nd_ispot ) {
        if ( MPOS(d1) < MPOS(d2) ) return 1;
        else if ( MPOS(d1) > MPOS(d2) ) return -1;
    }
    if ( c = ndl_block_compare(d1,d2) ) return c;
    if ( !nd_ispot ) {
        if ( MPOS(d1) < MPOS(d2) ) return 1;
        else if ( MPOS(d1) > MPOS(d2) ) return -1;
    }
    return 0;
}

int ndl_module_matrix_compare(UINT *d1,UINT *d2)
{
    int i,c;

    if ( nd_ispot ) {
        if ( MPOS(d1) < MPOS(d2) ) return 1;
        else if ( MPOS(d1) > MPOS(d2) ) return -1;
    }
    if ( c = ndl_matrix_compare(d1,d2) ) return c;
    if ( !nd_ispot ) {
        if ( MPOS(d1) < MPOS(d2) ) return 1;
        else if ( MPOS(d1) > MPOS(d2) ) return -1;
    }
    return 0;
}

int ndl_module_composite_compare(UINT *d1,UINT *d2)
{
    int i,c;

    if ( nd_ispot ) {
        if ( MPOS(d1) > MPOS(d2) ) return 1;
        else if ( MPOS(d1) < MPOS(d2) ) return -1;
    }
    if ( c = ndl_composite_compare(d1,d2) ) return c;
    if ( !nd_ispot ) {
        if ( MPOS(d1) > MPOS(d2) ) return 1;
        else if ( MPOS(d1) < MPOS(d2) ) return -1;
    }
    return 0;
}

INLINE int ndl_equal(UINT *d1,UINT *d2)
{
    int i;

    switch ( nd_wpd ) {
        case 2:
            if ( TD(d2) != TD(d1) ) return 0;
            if ( d2[1] != d1[1] ) return 0;
            return 1;
            break;
        case 3:
            if ( TD(d2) != TD(d1) ) return 0;
            if ( d2[1] != d1[1] ) return 0;
            if ( d2[2] != d1[2] ) return 0;
            return 1;
            break;
        default:
            for ( i = 0; i < nd_wpd; i++ )
                if ( *d1++ != *d2++ ) return 0;
            return 1;
            break;
    }
}

INLINE void ndl_copy(UINT *d1,UINT *d2)
{
    int i;

    switch ( nd_wpd ) {
        case 2:
            TD(d2) = TD(d1);
            d2[1] = d1[1];
            break;
        case 3:
            TD(d2) = TD(d1);
            d2[1] = d1[1];
            d2[2] = d1[2];
            break;
        default:
            for ( i = 0; i < nd_wpd; i++ )
                d2[i] = d1[i];
            break;
    }
}

INLINE void ndl_zero(UINT *d)
{
    int i;
    for ( i = 0; i < nd_wpd; i++ ) d[i] = 0;
}

INLINE void ndl_add(UINT *d1,UINT *d2,UINT *d)
{
    int i;

    if ( nd_module ) {
        if ( MPOS(d1) && MPOS(d2) && (MPOS(d1) != MPOS(d2)) ) 
        error("ndl_add : invalid operation");
    }
#if 1
    switch ( nd_wpd ) {
        case 2:
            TD(d) = TD(d1)+TD(d2);
            d[1] = d1[1]+d2[1];
            break;
        case 3:
            TD(d) = TD(d1)+TD(d2);
            d[1] = d1[1]+d2[1];
            d[2] = d1[2]+d2[2];
            break;
        default:
            for ( i = 0; i < nd_wpd; i++ ) d[i] = d1[i]+d2[i];
            break;
    }
#else
    for ( i = 0; i < nd_wpd; i++ ) d[i] = d1[i]+d2[i];
#endif
}

/* d1 += d2 */
INLINE void ndl_addto(UINT *d1,UINT *d2)
{
    int i;

    if ( nd_module ) {
        if ( MPOS(d1) && MPOS(d2) && (MPOS(d1) != MPOS(d2)) ) 
            error("ndl_addto : invalid operation");
    }
#if 1
    switch ( nd_wpd ) {
        case 2:
            TD(d1) += TD(d2);
            d1[1] += d2[1];
            break;
        case 3:
            TD(d1) += TD(d2);
            d1[1] += d2[1];
            d1[2] += d2[2];
            break;
        default:
            for ( i = 0; i < nd_wpd; i++ ) d1[i] += d2[i];
            break;
    }
#else
    for ( i = 0; i < nd_wpd; i++ ) d1[i] += d2[i];
#endif
}

INLINE void ndl_sub(UINT *d1,UINT *d2,UINT *d)
{
    int i;

    for ( i = 0; i < nd_wpd; i++ ) d[i] = d1[i]-d2[i];
}

int ndl_disjoint(UINT *d1,UINT *d2)
{
    UINT t1,t2,u,u1,u2;
    int i,j;

    if ( nd_module && (MPOS(d1) == MPOS(d2)) ) return 0;
#if USE_UNROLL
    switch ( nd_bpe ) {
        case 3:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                t1 = u1&0x38000000; t2 = u2&0x38000000; if ( t1&&t2 ) return 0;
                t1 = u1& 0x7000000; t2 = u2& 0x7000000; if ( t1&&t2 ) return 0;
                t1 = u1&  0xe00000; t2 = u2&  0xe00000; if ( t1&&t2 ) return 0;
                t1 = u1&  0x1c0000; t2 = u2&  0x1c0000; if ( t1&&t2 ) return 0;
                t1 = u1&   0x38000; t2 = u2&   0x38000; if ( t1&&t2 ) return 0;
                t1 = u1&    0x7000; t2 = u2&    0x7000; if ( t1&&t2 ) return 0;
                t1 = u1&     0xe00; t2 = u2&     0xe00; if ( t1&&t2 ) return 0;
                t1 = u1&     0x1c0; t2 = u2&     0x1c0; if ( t1&&t2 ) return 0;
                t1 = u1&      0x38; t2 = u2&      0x38; if ( t1&&t2 ) return 0;
                t1 = u1&       0x7; t2 = u2&       0x7; if ( t1&&t2 ) return 0;
            }
            return 1;
            break;
        case 4:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                t1 = u1&0xf0000000; t2 = u2&0xf0000000; if ( t1&&t2 ) return 0;
                t1 = u1& 0xf000000; t2 = u2& 0xf000000; if ( t1&&t2 ) return 0;
                t1 = u1&  0xf00000; t2 = u2&  0xf00000; if ( t1&&t2 ) return 0;
                t1 = u1&   0xf0000; t2 = u2&   0xf0000; if ( t1&&t2 ) return 0;
                t1 = u1&    0xf000; t2 = u2&    0xf000; if ( t1&&t2 ) return 0;
                t1 = u1&     0xf00; t2 = u2&     0xf00; if ( t1&&t2 ) return 0;
                t1 = u1&      0xf0; t2 = u2&      0xf0; if ( t1&&t2 ) return 0;
                t1 = u1&       0xf; t2 = u2&       0xf; if ( t1&&t2 ) return 0;
            }
            return 1;
            break;
        case 6:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                t1 = u1&0x3f000000; t2 = u2&0x3f000000; if ( t1&&t2 ) return 0;
                t1 = u1&  0xfc0000; t2 = u2&  0xfc0000; if ( t1&&t2 ) return 0;
                t1 = u1&   0x3f000; t2 = u2&   0x3f000; if ( t1&&t2 ) return 0;
                t1 = u1&     0xfc0; t2 = u2&     0xfc0; if ( t1&&t2 ) return 0;
                t1 = u1&      0x3f; t2 = u2&      0x3f; if ( t1&&t2 ) return 0;
            }
            return 1;
            break;
        case 8:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                t1 = u1&0xff000000; t2 = u2&0xff000000; if ( t1&&t2 ) return 0;
                t1 = u1&  0xff0000; t2 = u2&  0xff0000; if ( t1&&t2 ) return 0;
                t1 = u1&    0xff00; t2 = u2&    0xff00; if ( t1&&t2 ) return 0;
                t1 = u1&      0xff; t2 = u2&      0xff; if ( t1&&t2 ) return 0;
            }
            return 1;
            break;
        case 16:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                t1 = u1&0xffff0000; t2 = u2&0xffff0000; if ( t1&&t2 ) return 0;
                t1 = u1&    0xffff; t2 = u2&    0xffff; if ( t1&&t2 ) return 0;
            }
            return 1;
            break;
        case 32:
            for ( i = nd_exporigin; i < nd_wpd; i++ )
                if ( d1[i] && d2[i] ) return 0;
            return 1;
            break;
        default:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u1 = d1[i]; u2 = d2[i];
                for ( j = 0; j < nd_epw; j++ ) {
                    if ( (u1&nd_mask0) && (u2&nd_mask0) ) return 0;
                    u1 >>= nd_bpe; u2 >>= nd_bpe;
                }
            }
            return 1;
            break;
    }
#else
    for ( i = nd_exporigin; i < nd_wpd; i++ ) {
        u1 = d1[i]; u2 = d2[i];
        for ( j = 0; j < nd_epw; j++ ) {
            if ( (u1&nd_mask0) && (u2&nd_mask0) ) return 0;
            u1 >>= nd_bpe; u2 >>= nd_bpe;
        }
    }
    return 1;
#endif
}

int ndl_check_bound(UINT *d1,UINT *d2)
{
    UINT u2;
    int i,j,ind,k;

    ind = 0;
#if USE_UNROLL
    switch ( nd_bpe ) {
        case 3:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u2 = d2[i];
                if ( d1[ind++]+((u2>>27)&0x7) >= 0x8 ) return 1;
                if ( d1[ind++]+((u2>>24)&0x7) >= 0x8 ) return 1;
                if ( d1[ind++]+((u2>>21)&0x7) >= 0x8 ) return 1;
                if ( d1[ind++]+((u2>>18)&0x7) >= 0x8 ) return 1;
                if ( d1[ind++]+((u2>>15)&0x7) >= 0x8 ) return 1;
                if ( d1[ind++]+((u2>>12)&0x7) >= 0x8 ) return 1;
                if ( d1[ind++]+((u2>>9)&0x7) >= 0x8 ) return 1;
                if ( d1[ind++]+((u2>>6)&0x7) >= 0x8 ) return 1;
                if ( d1[ind++]+((u2>>3)&0x7) >= 0x8 ) return 1;
                if ( d1[ind++]+(u2&0x7) >= 0x8 ) return 1;
            }
            return 0;
            break;
        case 4:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u2 = d2[i];
                if ( d1[ind++]+((u2>>28)&0xf) >= 0x10 ) return 1;
                if ( d1[ind++]+((u2>>24)&0xf) >= 0x10 ) return 1;
                if ( d1[ind++]+((u2>>20)&0xf) >= 0x10 ) return 1;
                if ( d1[ind++]+((u2>>16)&0xf) >= 0x10 ) return 1;
                if ( d1[ind++]+((u2>>12)&0xf) >= 0x10 ) return 1;
                if ( d1[ind++]+((u2>>8)&0xf) >= 0x10 ) return 1;
                if ( d1[ind++]+((u2>>4)&0xf) >= 0x10 ) return 1;
                if ( d1[ind++]+(u2&0xf) >= 0x10 ) return 1;
            }
            return 0;
            break;
        case 6:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u2 = d2[i];
                if ( d1[ind++]+((u2>>24)&0x3f) >= 0x40 ) return 1;
                if ( d1[ind++]+((u2>>18)&0x3f) >= 0x40 ) return 1;
                if ( d1[ind++]+((u2>>12)&0x3f) >= 0x40 ) return 1;
                if ( d1[ind++]+((u2>>6)&0x3f) >= 0x40 ) return 1;
                if ( d1[ind++]+(u2&0x3f) >= 0x40 ) return 1;
            }
            return 0;
            break;
        case 8:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u2 = d2[i];
                if ( d1[ind++]+((u2>>24)&0xff) >= 0x100 ) return 1;
                if ( d1[ind++]+((u2>>16)&0xff) >= 0x100 ) return 1;
                if ( d1[ind++]+((u2>>8)&0xff) >= 0x100 ) return 1;
                if ( d1[ind++]+(u2&0xff) >= 0x100 ) return 1;
            }
            return 0;
            break;
        case 16:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u2 = d2[i];
                if ( d1[ind++]+((u2>>16)&0xffff) > 0x10000 ) return 1;
                if ( d1[ind++]+(u2&0xffff) > 0x10000 ) return 1;
            }
            return 0;
            break;
        case 32:
            for ( i = nd_exporigin; i < nd_wpd; i++ )
                if ( d1[i]+d2[i]<d1[i] ) return 1;
            return 0;
            break;
        default:
            for ( i = nd_exporigin; i < nd_wpd; i++ ) {
                u2 = d2[i];
                k = (nd_epw-1)*nd_bpe;
                for ( j = 0; j < nd_epw; j++, k -= nd_bpe )
                    if ( d1[ind++]+((u2>>k)&nd_mask0) > nd_mask0 ) return 1;
            }
            return 0;
            break;
    }
#else
    for ( i = nd_exporigin; i < nd_wpd; i++ ) {
        u2 = d2[i];
        k = (nd_epw-1)*nd_bpe;
        for ( j = 0; j < nd_epw; j++, k -= nd_bpe )
            if ( d1[ind++]+((u2>>k)&nd_mask0) > nd_mask0 ) return 1;
    }
    return 0;
#endif
}

int ndl_check_bound2(int index,UINT *d2)
{
    return ndl_check_bound(nd_bound[index],d2);
}

INLINE int ndl_hash_value(UINT *d)
{
    int i;
    int r;

    r = 0;
    for ( i = 0; i < nd_wpd; i++ )    
        r = ((r<<16)+d[i])%REDTAB_LEN;
    return r;
}

INLINE int ndl_find_reducer(UINT *dg)
{
    RHist r;
    int d,k,i;

    d = ndl_hash_value(dg);
    for ( r = nd_red[d], k = 0; r; r = NEXT(r), k++ ) {
        if ( ndl_equal(dg,DL(r)) ) {
            if ( k > 0 ) nd_notfirst++;
            nd_found++;
            return r->index;
        }
    }
    if ( Reverse )
        for ( i = nd_psn-1; i >= 0; i-- ) {
            r = nd_psh[i];
            if ( ndl_reducible(dg,DL(r)) ) {
                nd_create++;
                nd_append_red(dg,i);
                return i;
            }
        }
    else
        for ( i = 0; i < nd_psn; i++ ) {
            r = nd_psh[i];
            if ( ndl_reducible(dg,DL(r)) ) {
                nd_create++;
                nd_append_red(dg,i);
                return i;
            }
        }
    return -1;
}

ND nd_merge(ND p1,ND p2)
{
    int n,c;
    int t,can,td1,td2;
    ND r;
    NM m1,m2,mr0,mr,s;

    if ( !p1 ) return p2;
    else if ( !p2 ) return p1;
    else {
        can = 0;
        for ( n = NV(p1), m1 = BDY(p1), m2 = BDY(p2), mr0 = 0; m1 && m2; ) {
            c = DL_COMPARE(DL(m1),DL(m2));
            switch ( c ) {
                case 0:
                    s = m1; m1 = NEXT(m1);
                    can++; NEXTNM2(mr0,mr,s);
                    s = m2; m2 = NEXT(m2); FREENM(s);
                    break;
                case 1:
                    s = m1; m1 = NEXT(m1); NEXTNM2(mr0,mr,s);
                    break;
                case -1:
                    s = m2; m2 = NEXT(m2); NEXTNM2(mr0,mr,s);
                    break;
            }
        }
        if ( !mr0 )
            if ( m1 ) mr0 = m1;
            else if ( m2 ) mr0 = m2;
            else return 0;
        else if ( m1 ) NEXT(mr) = m1;
        else if ( m2 ) NEXT(mr) = m2;
        else NEXT(mr) = 0;
        BDY(p1) = mr0;
        SG(p1) = MAX(SG(p1),SG(p2));
        LEN(p1) = LEN(p1)+LEN(p2)-can;
        FREEND(p2);
        return p1;
    }
}

ND nd_add(int mod,ND p1,ND p2)
{
    int n,c;
    int t,can,td1,td2;
    ND r;
    NM m1,m2,mr0,mr,s;

    if ( !p1 ) return p2;
    else if ( !p2 ) return p1;
    else if ( mod == -1 ) return nd_add_sf(p1,p2);
    else if ( !mod ) return nd_add_q(p1,p2);
    else {
        can = 0;
        for ( n = NV(p1), m1 = BDY(p1), m2 = BDY(p2), mr0 = 0; m1 && m2; ) {
            c = DL_COMPARE(DL(m1),DL(m2));
            switch ( c ) {
                case 0:
                    t = ((CM(m1))+(CM(m2))) - mod;
                    if ( t < 0 ) t += mod;
                    s = m1; m1 = NEXT(m1);
                    if ( t ) {
                        can++; NEXTNM2(mr0,mr,s); CM(mr) = (t);
                    } else {
                        can += 2; FREENM(s);
                    }
                    s = m2; m2 = NEXT(m2); FREENM(s);
                    break;
                case 1:
                    s = m1; m1 = NEXT(m1); NEXTNM2(mr0,mr,s);
                    break;
                case -1:
                    s = m2; m2 = NEXT(m2); NEXTNM2(mr0,mr,s);
                    break;
            }
        }
        if ( !mr0 )
            if ( m1 ) mr0 = m1;
            else if ( m2 ) mr0 = m2;
            else return 0;
        else if ( m1 ) NEXT(mr) = m1;
        else if ( m2 ) NEXT(mr) = m2;
        else NEXT(mr) = 0;
        BDY(p1) = mr0;
        SG(p1) = MAX(SG(p1),SG(p2));
        LEN(p1) = LEN(p1)+LEN(p2)-can;
        FREEND(p2);
        return p1;
    }
}

/* XXX on opteron, the inlined manipulation of destructive additon of
 * two NM seems to make gcc optimizer get confused, so the part is
 * done in a function.
 */

int nm_destructive_add_q(NM *m1,NM *m2,NM *mr0,NM *mr)
{
    NM s;
    P t;
    int can;

    addp(nd_vc,CP(*m1),CP(*m2),&t);
    s = *m1; *m1 = NEXT(*m1);
    if ( t ) {
        can = 1; NEXTNM2(*mr0,*mr,s); CP(*mr) = (t);
    } else {
        can = 2; FREENM(s);
    }
    s = *m2; *m2 = NEXT(*m2); FREENM(s);
    return can;
}

ND nd_add_q(ND p1,ND p2)
{
    int n,c,can;
    ND r;
    NM m1,m2,mr0,mr,s;
    P t;

    if ( !p1 ) return p2;
    else if ( !p2 ) return p1;
    else {
        can = 0;
        for ( n = NV(p1), m1 = BDY(p1), m2 = BDY(p2), mr0 = 0; m1 && m2; ) {
            c = DL_COMPARE(DL(m1),DL(m2));
            switch ( c ) {
                case 0:
#if defined(__x86_64__)
                    can += nm_destructive_add_q(&m1,&m2,&mr0,&mr);
#else
                    addp(nd_vc,CP(m1),CP(m2),&t);
                    s = m1; m1 = NEXT(m1);
                    if ( t ) {
                        can++; NEXTNM2(mr0,mr,s); CP(mr) = (t);
                    } else {
                        can += 2; FREENM(s);
                    }
                    s = m2; m2 = NEXT(m2); FREENM(s);
#endif
                    break;
                case 1:
                    s = m1; m1 = NEXT(m1); NEXTNM2(mr0,mr,s);
                    break;
                case -1:
                    s = m2; m2 = NEXT(m2); NEXTNM2(mr0,mr,s);
                    break;
            }
        }
        if ( !mr0 )
            if ( m1 ) mr0 = m1;
            else if ( m2 ) mr0 = m2;
            else return 0;
        else if ( m1 ) NEXT(mr) = m1;
        else if ( m2 ) NEXT(mr) = m2;
        else NEXT(mr) = 0;
        BDY(p1) = mr0;
        SG(p1) = MAX(SG(p1),SG(p2));
        LEN(p1) = LEN(p1)+LEN(p2)-can;
        FREEND(p2);
        return p1;
    }
}

ND nd_add_sf(ND p1,ND p2)
{
    int n,c,can;
    ND r;
    NM m1,m2,mr0,mr,s;
    int t;

    if ( !p1 ) return p2;
    else if ( !p2 ) return p1;
    else {
        can = 0;
        for ( n = NV(p1), m1 = BDY(p1), m2 = BDY(p2), mr0 = 0; m1 && m2; ) {
            c = DL_COMPARE(DL(m1),DL(m2));
            switch ( c ) {
                case 0:
                    t = _addsf(CM(m1),CM(m2));
                    s = m1; m1 = NEXT(m1);
                    if ( t ) {
                        can++; NEXTNM2(mr0,mr,s); CM(mr) = (t);
                    } else {
                        can += 2; FREENM(s);
                    }
                    s = m2; m2 = NEXT(m2); FREENM(s);
                    break;
                case 1:
                    s = m1; m1 = NEXT(m1); NEXTNM2(mr0,mr,s);
                    break;
                case -1:
                    s = m2; m2 = NEXT(m2); NEXTNM2(mr0,mr,s);
                    break;
            }
        }
        if ( !mr0 )
            if ( m1 ) mr0 = m1;
            else if ( m2 ) mr0 = m2;
            else return 0;
        else if ( m1 ) NEXT(mr) = m1;
        else if ( m2 ) NEXT(mr) = m2;
        else NEXT(mr) = 0;
        BDY(p1) = mr0;
        SG(p1) = MAX(SG(p1),SG(p2));
        LEN(p1) = LEN(p1)+LEN(p2)-can;
        FREEND(p2);
        return p1;
    }
}

ND nd_reduce2(int mod,ND d,ND g,NDV p,NM mul,NDC dn,Obj *divp)
{
    int c,c1,c2;
    Q cg,cred,gcd,tq;
    P cgp,credp,gcdp;
    Obj tr,tr1;

    if ( mod == -1 ) {
        CM(mul) = _mulsf(_invsf(HCM(p)),_chsgnsf(HCM(g)));
        *divp = (Obj)ONE;
    } else if ( mod ) {
        c1 = invm(HCM(p),mod); c2 = mod-HCM(g);
        DMAR(c1,c2,0,mod,c); CM(mul) = c;
        *divp = (Obj)ONE;
    } else if ( nd_vc ) {
        ezgcdpz(nd_vc,HCP(g),HCP(p),&gcdp);
        divsp(nd_vc,HCP(g),gcdp,&cgp); divsp(nd_vc,HCP(p),gcdp,&credp);
        chsgnp(cgp,&CP(mul));
        nd_mul_c_q(d,credp); nd_mul_c_q(g,credp);
        if ( dn ) {
            mulr(nd_vc,(Obj)dn->r,(Obj)credp,&tr);
            reductr(nd_vc,tr,&tr1); dn->r = (R)tr1;
        }
        *divp = (Obj)credp;
    } else {
        igcd_cofactor(HCQ(g),HCQ(p),&gcd,&cg,&cred);
        chsgnq(cg,&CQ(mul));
        nd_mul_c_q(d,(P)cred); nd_mul_c_q(g,(P)cred);
        if ( dn ) {
            mulq(dn->z,cred,&tq); dn->z = tq;
        }
        *divp = (Obj)cred;
    }
    return nd_add(mod,g,ndv_mul_nm(mod,mul,p));
}

/* ret=1 : success, ret=0 : overflow */
int nd_nf(int mod,ND d,ND g,NDV *ps,int full,NDC dn,ND *rp)
{
    NM m,mrd,tail;
    NM mul;
    int n,sugar,psugar,sugar0,stat,index;
    int c,c1,c2,dummy;
    RHist h;
    NDV p,red;
    Q cg,cred,gcd,tq,qq,iq;
    DP dmul;
    NODE node;
    LIST hist;
    double hmag;
    P tp,tp1;
    Obj tr,tr1,div;
    union oNDC hg;
    P cont;

    if ( dn ) {
        if ( mod )
            dn->m = 1;
        else if ( nd_vc )
            dn->r = (R)ONE;
        else
            dn->z = ONE;
    }
    if ( !g ) {
        *rp = d;
        return 1;
    }
    if ( !mod ) hmag = ((double)p_mag(HCP(g)))*nd_scale;

    sugar0 = sugar = SG(g);
    n = NV(g);
    mul = (NM)ALLOCA(sizeof(struct oNM)+(nd_wpd-1)*sizeof(UINT));
    if ( d )
        for ( tail = BDY(d); NEXT(tail); tail = NEXT(tail) );
    for ( ; g; ) {
        index = ndl_find_reducer(HDL(g));
        if ( index >= 0 ) {
            h = nd_psh[index];
            ndl_sub(HDL(g),DL(h),DL(mul));
            if ( ndl_check_bound2(index,DL(mul)) ) {
                nd_free(g); nd_free(d);
                return 0;
            }
            p = nd_demand ? ndv_load(index) : ps[index];
            /* d+g -> div*(d+g)+mul*p */
            g = nd_reduce2(mod,d,g,p,mul,dn,&div);
            if ( GenTrace ) {
                /* Trace=[div,index,mul,ONE] */
                STOQ(index,iq);
                nmtodp(mod,mul,&dmul);
                node = mknode(4,div,iq,dmul,ONE);
            }
            sugar = MAX(sugar,SG(p)+TD(DL(mul)));
            if ( !mod && g && ((double)(p_mag(HCP(g))) > hmag) ) {
                hg = HCU(g);
                nd_removecont2(d,g);
                if ( dn || GenTrace ) {
                    /* overwrite cont : Trace=[div,index,mul,cont] */
                    cont = ndc_div(mod,hg,HCU(g));
                    if ( dn ) {
                        if ( nd_vc ) {
                            divr(nd_vc,(Obj)dn->r,(Obj)cont,&tr);
                            reductr(nd_vc,(Obj)tr,&tr1); dn->r = (R)tr1;
                        } else divq(dn->z,(Q)cont,&dn->z);
                    }
                    if ( GenTrace && !UNIQ(cont) ) ARG3(node) = (pointer)cont;
                }
                hmag = ((double)p_mag(HCP(g)))*nd_scale;
            }
            MKLIST(hist,node);
            MKNODE(node,hist,nd_tracelist); nd_tracelist = node;
        } else if ( !full ) {
            *rp = g;
            return 1;
        } else {
            m = BDY(g); 
            if ( NEXT(m) ) {
                BDY(g) = NEXT(m); NEXT(m) = 0; LEN(g)--;
            } else {
                FREEND(g); g = 0;
            }
            if ( d ) {
                NEXT(tail)=m; tail=m; LEN(d)++;
            } else {
                MKND(n,m,1,d); tail = BDY(d);
            }
        }
    }
    if ( d ) SG(d) = sugar;
    *rp = d;
    return 1;
}

int nd_nf_pbucket(int mod,ND g,NDV *ps,int full,ND *rp)
{
    int hindex,index;
    NDV p;
    ND u,d,red;
    NODE l;
    NM mul,m,mrd,tail;
    int sugar,psugar,n,h_reducible;
    PGeoBucket bucket;
    int c,c1,c2;
    Q cg,cred,gcd,zzz;
    RHist h;
    double hmag,gmag;
    int count = 0;
    int hcount = 0;

    if ( !g ) {
        *rp = 0;
        return 1;
    }
    sugar = SG(g);
    n = NV(g);
    if ( !mod ) hmag = ((double)p_mag((P)HCQ(g)))*nd_scale;
    bucket = create_pbucket();
    add_pbucket(mod,bucket,g);
    d = 0;
    mul = (NM)ALLOCA(sizeof(struct oNM)+(nd_wpd-1)*sizeof(UINT));
    while ( 1 ) {
        hindex = mod?head_pbucket(mod,bucket):head_pbucket_q(bucket);
        if ( hindex < 0 ) {
            if ( DP_Print > 3 ) printf("(%d %d)",count,hcount);
            if ( d ) SG(d) = sugar;
            *rp = d;
            return 1;
        }
        g = bucket->body[hindex];
        index = ndl_find_reducer(HDL(g));
        if ( index >= 0 ) {
            count++;
            if ( !d ) hcount++;
            h = nd_psh[index];
            ndl_sub(HDL(g),DL(h),DL(mul));
            if ( ndl_check_bound2(index,DL(mul)) ) {
                nd_free(d);
                free_pbucket(bucket);
                *rp = 0;
                return 0;
            }
            p = ps[index];
            if ( mod == -1 )
                CM(mul) = _mulsf(_invsf(HCM(p)),_chsgnsf(HCM(g)));
             else if ( mod ) {
                c1 = invm(HCM(p),mod); c2 = mod-HCM(g);
                DMAR(c1,c2,0,mod,c); CM(mul) = c;
            } else {
                igcd_cofactor(HCQ(g),HCQ(p),&gcd,&cg,&cred);
                chsgnq(cg,&CQ(mul));
                nd_mul_c_q(d,(P)cred);
                mulq_pbucket(bucket,cred);
                g = bucket->body[hindex];
                gmag = (double)p_mag((P)HCQ(g));
            }
            red = ndv_mul_nm(mod,mul,p);
            bucket->body[hindex] = nd_remove_head(g);
            red = nd_remove_head(red);
            add_pbucket(mod,bucket,red);
            psugar = SG(p)+TD(DL(mul));
            sugar = MAX(sugar,psugar);
            if ( !mod && hmag && (gmag > hmag) ) {
                g = normalize_pbucket(mod,bucket);
                if ( !g ) {
                    if ( d ) SG(d) = sugar;
                    *rp = d;
                    return 1;
                }
                nd_removecont2(d,g);
                hmag = ((double)p_mag((P)HCQ(g)))*nd_scale;
                add_pbucket(mod,bucket,g);
            }
        } else if ( !full ) {
            g = normalize_pbucket(mod,bucket);
            if ( g ) SG(g) = sugar;
            *rp = g;
            return 1;
        } else {
            m = BDY(g); 
            if ( NEXT(m) ) {
                BDY(g) = NEXT(m); NEXT(m) = 0; LEN(g)--;
            } else {
                FREEND(g); g = 0;
            }
            bucket->body[hindex] = g;
            NEXT(m) = 0;
            if ( d ) {
                NEXT(tail)=m; tail=m; LEN(d)++;
            } else {
                MKND(n,m,1,d); tail = BDY(d);
            }
        }
    }
}

/* input : list of NDV, cand : list of NDV */

int ndv_check_membership(int m,NODE input,int obpe,int oadv,EPOS oepos,NODE cand)
{
    int n,i,stat;
    ND nf,d;
    NDV r;
    NODE t,s;
    union oNDC dn;
    Q q;
    LIST list;

    ndv_setup(m,0,cand,GenTrace?1:0,1);
    n = length(cand);

	if ( GenTrace ) { nd_alltracelist = 0; nd_tracelist = 0; }
    /* membercheck : list is a subset of Id(cand) ? */
    for ( t = input, i = 0; t; t = NEXT(t), i++ ) {
again:
		nd_tracelist = 0;
        if ( nd_bpe > obpe )
            r = ndv_dup_realloc((NDV)BDY(t),obpe,oadv,oepos);
        else
            r = (NDV)BDY(t);
        d = ndvtond(m,r);
        stat = nd_nf(m,0,d,nd_ps,0,0,&nf);
        if ( !stat ) {
            nd_reconstruct(0,0);
            goto again;
        } else if ( nf ) return 0;
		if ( GenTrace ) {
			nd_tracelist = reverse_node(nd_tracelist);
			MKLIST(list,nd_tracelist);
			STOQ(i,q); s = mknode(2,q,list); MKLIST(list,s);
			MKNODE(s,list,nd_alltracelist);
			nd_alltracelist = s; nd_tracelist = 0;
		}
        if ( DP_Print ) { printf("."); fflush(stdout); }
    }
    if ( DP_Print ) { printf("\n"); }
    return 1;
}

ND nd_remove_head(ND p)
{
    NM m;

    m = BDY(p);
    if ( !NEXT(m) ) {
        FREEND(p); p = 0;
    } else {
        BDY(p) = NEXT(m); LEN(p)--;
    }
    FREENM(m);
    return p;
}

ND nd_separate_head(ND p,ND *head)
{
    NM m,m0;
    ND r;

    m = BDY(p);
    if ( !NEXT(m) ) {
        *head = p; p = 0;
    } else {
        m0 = m;
        BDY(p) = NEXT(m); LEN(p)--;
        NEXT(m0) = 0;
        MKND(NV(p),m0,1,r);
        *head = r;
    }
    return p;
}

PGeoBucket create_pbucket()
{
    PGeoBucket g;
     
    g = CALLOC(1,sizeof(struct oPGeoBucket));
    g->m = -1;
    return g;
}

void free_pbucket(PGeoBucket b) {
    int i;

    for ( i = 0; i <= b->m; i++ )
        if ( b->body[i] ) {
            nd_free(b->body[i]);
            b->body[i] = 0;
        }
    GC_free(b);
}

void add_pbucket_symbolic(PGeoBucket g,ND d)
{
    int l,i,k,m;

    if ( !d )
        return;
    l = LEN(d);
    for ( k = 0, m = 1; l > m; k++, m <<= 1 );
    /* 2^(k-1) < l <= 2^k (=m) */
    d = nd_merge(g->body[k],d);
    for ( ; d && LEN(d) > m; k++, m <<= 1 ) {
        g->body[k] = 0;
        d = nd_merge(g->body[k+1],d);
    }
    g->body[k] = d;
    g->m = MAX(g->m,k);
}

void add_pbucket(int mod,PGeoBucket g,ND d)
{
    int l,i,k,m;

    if ( !d )
        return;
    l = LEN(d);
    for ( k = 0, m = 1; l > m; k++, m <<= 1 );
    /* 2^(k-1) < l <= 2^k (=m) */
    d = nd_add(mod,g->body[k],d);
    for ( ; d && LEN(d) > m; k++, m <<= 1 ) {
        g->body[k] = 0;
        d = nd_add(mod,g->body[k+1],d);
    }
    g->body[k] = d;
    g->m = MAX(g->m,k);
}

void mulq_pbucket(PGeoBucket g,Q c)
{
    int k;

    for ( k = 0; k <= g->m; k++ )
        nd_mul_c_q(g->body[k],(P)c);
}

NM remove_head_pbucket_symbolic(PGeoBucket g)
{
    int j,i,k,c;
    NM head;
    
    k = g->m;
    j = -1;
    for ( i = 0; i <= k; i++ ) {
        if ( !g->body[i] ) continue;
        if ( j < 0 ) j = i;
        else {
            c = DL_COMPARE(HDL(g->body[i]),HDL(g->body[j]));
            if ( c > 0 )
                j = i;
            else if ( c == 0 )
                g->body[i] = nd_remove_head(g->body[i]);
        }
    }
    if ( j < 0 ) return 0;
    else {
        head = BDY(g->body[j]);
        if ( !NEXT(head) ) {
            FREEND(g->body[j]);
            g->body[j] = 0;
        } else {
            BDY(g->body[j]) = NEXT(head);
            LEN(g->body[j])--;
        }
        return head;
    }
}

int head_pbucket(int mod,PGeoBucket g)
{
    int j,i,c,k,nv,sum;
    UINT *di,*dj;
    ND gi,gj;

    k = g->m;
    while ( 1 ) {
        j = -1;
        for ( i = 0; i <= k; i++ ) {
            if ( !(gi = g->body[i]) )
                continue;
            if ( j < 0 ) {
                j = i;
                gj = g->body[j];
                dj = HDL(gj);
                sum = HCM(gj);
            } else {
                c = DL_COMPARE(HDL(gi),dj);
                if ( c > 0 ) {
                    if ( sum ) HCM(gj) = sum;
                    else g->body[j] = nd_remove_head(gj);
                    j = i;
                    gj = g->body[j];
                    dj = HDL(gj);
                    sum = HCM(gj);
                } else if ( c == 0 ) {
                    if ( mod == -1 )
                        sum = _addsf(sum,HCM(gi));
                    else {
                        sum = sum+HCM(gi)-mod;
                        if ( sum < 0 ) sum += mod;
                    }
                    g->body[i] = nd_remove_head(gi);
                }
            }
        }
        if ( j < 0 ) return -1;
        else if ( sum ) {
            HCM(gj) = sum;
            return j;
        } else
            g->body[j] = nd_remove_head(gj);
    }
}

int head_pbucket_q(PGeoBucket g)
{
    int j,i,c,k,nv;
    Q sum,t;
    ND gi,gj;

    k = g->m;
    while ( 1 ) {
        j = -1;
        for ( i = 0; i <= k; i++ ) {
            if ( !(gi = g->body[i]) ) continue;
            if ( j < 0 ) {
                j = i;
                gj = g->body[j];
                sum = HCQ(gj);
            } else {
                nv = NV(gi);
                c = DL_COMPARE(HDL(gi),HDL(gj));
                if ( c > 0 ) {
                    if ( sum ) HCQ(gj) = sum;
                    else g->body[j] = nd_remove_head(gj);
                    j = i;
                    gj = g->body[j];
                    sum = HCQ(gj);
                } else if ( c == 0 ) {
                    addq(sum,HCQ(gi),&t);
                    sum = t;
                    g->body[i] = nd_remove_head(gi);
                }
            }
        }
        if ( j < 0 ) return -1;
        else if ( sum ) {
            HCQ(gj) = sum;
            return j;
        } else
            g->body[j] = nd_remove_head(gj);
    }
}

ND normalize_pbucket(int mod,PGeoBucket g)
{
    int i;
    ND r,t;

    r = 0;
    for ( i = 0; i <= g->m; i++ ) {
        r = nd_add(mod,r,g->body[i]);
        g->body[i] = 0;
    }
    g->m = -1;
    return r;
}

#if 0
void register_hcf(NDV p)
{
    DCP dc,t;
    P hc,h;
    int c;
    NODE l,l1,prev;

    hc = p->body->c.p;
    if ( !nd_vc || NUM(hc) ) return;
    fctrp(nd_vc,hc,&dc);
    for ( t = dc; t; t = NEXT(t) ) {
        h = t->c;
        if ( NUM(h) ) continue;
        for ( prev = 0, l = nd_hcf; l; prev = l, l = NEXT(l) ) {
            c = compp(nd_vc,h,(P)BDY(l));
            if ( c >= 0 ) break;
        }
        if ( !l || c > 0  ) {
            MKNODE(l1,h,l);
            if ( !prev )
                nd_hcf = l1;
            else
                NEXT(prev) = l1;
        }
    }
}
#else
void register_hcf(NDV p)
{
    DCP dc,t;
    P hc,h,q;
    Q dmy;
    int c;
    NODE l,l1,prev;

    hc = p->body->c.p;
    if ( NUM(hc) ) return;
    ptozp(hc,1,&dmy,&h);
#if 1
    for ( l = nd_hcf; l; l = NEXT(l) ) {
        while ( 1 ) {
            if ( divtpz(nd_vc,h,(P)BDY(l),&q) ) h = q;
            else break;
        }
    }
    if ( NUM(h) ) return;
#endif
    for ( prev = 0, l = nd_hcf; l; prev = l, l = NEXT(l) ) {
        c = compp(nd_vc,h,(P)BDY(l));
        if ( c >= 0 ) break;
    }
    if ( !l || c > 0  ) {
        MKNODE(l1,h,l);
        if ( !prev )
            nd_hcf = l1;
        else
            NEXT(prev) = l1;
    }
}
#endif

int do_diagonalize(int sugar,int m)
{
    int i,nh,stat;
    NODE r,g,t;
    ND h,nf,s,head;
    NDV nfv;
    Q q,num,den;
    P nm,nmp,dn,mnp,dnp,cont,cont1;
    union oNDC hc;
    NODE node;
    LIST l;
    Q iq;

    for ( i = nd_psn-1; i >= 0 && SG(nd_psh[i]) == sugar; i-- ) {
        if ( GenTrace ) {
            /* Trace = [1,index,1,1] */
            STOQ(i,iq); node = mknode(4,ONE,iq,ONE,ONE);
            MKLIST(l,node); MKNODE(nd_tracelist,l,0);
        }
        if ( nd_demand )
            nfv = ndv_load(i);
        else
            nfv = nd_ps[i];
        s = ndvtond(m,nfv);
        s = nd_separate_head(s,&head);
        stat = nd_nf(m,head,s,nd_ps,1,0,&nf);
        if ( !stat ) return 0;
        ndv_free(nfv);
        hc = HCU(nf); nd_removecont(m,nf);
        cont = ndc_div(m,hc,HCU(nf));
		if ( GenTrace ) finalize_tracelist(i,cont);
        nfv = ndtondv(m,nf);
        nd_free(nf);
        nd_bound[i] = ndv_compute_bound(nfv);
        if ( !m ) register_hcf(nfv);
        if ( nd_demand ) {
            ndv_save(nfv,i);
            ndv_free(nfv);
        } else
            nd_ps[i] = nfv;
    }
    return 1;
}

/* return value = 0 => input is not a GB */

NODE nd_gb(int m,int ishomo,int checkonly,int gensyz,int **indp)
{
    int i,nh,sugar,stat;
    NODE r,g,t;
    ND_pairs d;
    ND_pairs l;
    ND h,nf,s,head,nf1;
    NDV nfv;
    Q q,num,den;
    union oNDC dn,hc;
    int diag_count = 0;
    P cont;
    LIST list;

    g = 0; d = 0;
    for ( i = 0; i < nd_psn; i++ ) {
        d = update_pairs(d,g,i,gensyz);
        g = update_base(g,i);
    }
    sugar = 0;
    while ( d ) {
again:
        l = nd_minp(d,&d);
        if ( SG(l) != sugar ) {
            if ( ishomo ) {
                diag_count = 0;
                stat = do_diagonalize(sugar,m);
                if ( !stat ) {
                    NEXT(l) = d; d = l;
                    d = nd_reconstruct(0,d);
                    goto again;
                }
            }
            sugar = SG(l);
            if ( DP_Print ) fprintf(asir_out,"%d",sugar);
        }
        stat = nd_sp(m,0,l,&h);
        if ( !stat ) {
            NEXT(l) = d; d = l;
            d = nd_reconstruct(0,d);
            goto again;
        }
#if USE_GEOBUCKET
        stat = (m&&!GenTrace)?nd_nf_pbucket(m,h,nd_ps,!Top,&nf)
               :nd_nf(m,0,h,nd_ps,!Top,0,&nf);
#else
        stat = nd_nf(m,0,h,nd_ps,!Top,0,&nf);
#endif
        if ( !stat ) {
            NEXT(l) = d; d = l;
            d = nd_reconstruct(0,d);
            goto again;
        } else if ( nf ) {
            if ( checkonly || gensyz ) return 0;
            if ( DP_Print ) { printf("+"); fflush(stdout); }
            hc = HCU(nf);
            nd_removecont(m,nf);
            if ( !m && nd_nalg ) {
                nd_monic(0,&nf);
                nd_removecont(m,nf);
            }
            if ( GenTrace ) {
				cont = ndc_div(m,hc,HCU(nf));
				if ( m || !UNIQ(cont) ) {
                    t = mknode(4,0,0,0,cont);
                    MKLIST(list,t); MKNODE(t,list,nd_tracelist);
					nd_tracelist = t;
				}
            }
            nfv = ndtondv(m,nf); nd_free(nf);
            nh = ndv_newps(m,nfv,0);
            if ( !m && (ishomo && ++diag_count == diag_period) ) {
                diag_count = 0;
                stat = do_diagonalize(sugar,m);
                if ( !stat ) {
                    NEXT(l) = d; d = l;
                    d = nd_reconstruct(1,d);
                    goto again;
                }
            }
            d = update_pairs(d,g,nh,0);
            g = update_base(g,nh);
            FREENDP(l);
        } else {
		    if ( GenTrace && gensyz ) {
                nd_tracelist = reverse_node(nd_tracelist); 
				MKLIST(list,nd_tracelist);
                STOQ(-1,q); t = mknode(2,q,list); MKLIST(list,t);
                MKNODE(t,list,nd_alltracelist); 
				nd_alltracelist = t; nd_tracelist = 0;
			}
            if ( DP_Print ) { printf("."); fflush(stdout); }
            FREENDP(l);
        }
    }
	conv_ilist(nd_demand,0,g,indp);
    if ( !checkonly && DP_Print ) { printf("nd_gb done.\n"); fflush(stdout); }
    return g;
}

int do_diagonalize_trace(int sugar,int m)
{
    int i,nh,stat;
    NODE r,g,t;
    ND h,nf,nfq,s,head;
    NDV nfv,nfqv;
    Q q,den,num;
    union oNDC hc;
    NODE node;
    LIST l;
    Q iq;
    P cont,cont1;

    for ( i = nd_psn-1; i >= 0 && SG(nd_psh[i]) == sugar; i-- ) {
        if ( GenTrace ) {
            /* Trace = [1,index,1,1] */
            STOQ(i,iq); node = mknode(4,ONE,iq,ONE,ONE);
            MKLIST(l,node); MKNODE(nd_tracelist,l,0);
        }
        /* for nd_ps */
        s = ndvtond(m,nd_ps[i]);
        s = nd_separate_head(s,&head);
        stat = nd_nf_pbucket(m,s,nd_ps,1,&nf);
        if ( !stat ) return 0;
        nf = nd_add(m,head,nf);
        ndv_free(nd_ps[i]);
        nd_ps[i] = ndtondv(m,nf);
        nd_free(nf);

        /* for nd_ps_trace */
        if ( nd_demand )
            nfv = ndv_load(i);
        else
            nfv = nd_ps_trace[i];
        s = ndvtond(0,nfv);
        s = nd_separate_head(s,&head);
        stat = nd_nf(0,head,s,nd_ps_trace,1,0,&nf);
        if ( !stat ) return 0;
        ndv_free(nfv);
        hc = HCU(nf); nd_removecont(0,nf);
		cont = ndc_div(0,hc,HCU(nf));
        if ( GenTrace ) finalize_tracelist(i,cont);
        nfv = ndtondv(0,nf);
        nd_free(nf);
        nd_bound[i] = ndv_compute_bound(nfv);
        register_hcf(nfv);
        if ( nd_demand ) {
            ndv_save(nfv,i);
            ndv_free(nfv);
        } else
            nd_ps_trace[i] = nfv;
    }
    return 1;
}

static struct oEGT eg_invdalg;
struct oEGT eg_le;

void nd_subst_vector(VL vl,P p,NODE subst,P *r)
{
    NODE tn;
    P p1;

    for ( tn = subst; tn; tn = NEXT(NEXT(tn)) ) {
        substp(vl,p,BDY(tn),BDY(NEXT(tn)),&p1); p = p1;
    }
    *r = p;
}

NODE nd_gb_trace(int m,int ishomo,int **indp)
{
    int i,nh,sugar,stat;
    NODE r,g,t;
    ND_pairs d;
    ND_pairs l;
    ND h,nf,nfq,s,head;
    NDV nfv,nfqv;
    Q q,den,num;
    P hc;
    union oNDC dn,hnfq;
    struct oEGT eg_monic,egm0,egm1;
    int diag_count = 0;
    P cont;
    LIST list;

    init_eg(&eg_monic);
    init_eg(&eg_invdalg);
    init_eg(&eg_le);
    g = 0; d = 0;
    for ( i = 0; i < nd_psn; i++ ) {
        d = update_pairs(d,g,i,0);
        g = update_base(g,i);
    }
    sugar = 0;
    while ( d ) {
again:
        l = nd_minp(d,&d);
        if ( SG(l) != sugar ) {
#if 1
            if ( ishomo ) {
                if ( DP_Print > 2 ) fprintf(asir_out,"|");
                stat = do_diagonalize_trace(sugar,m);
                if ( DP_Print > 2 ) fprintf(asir_out,"|");
                diag_count = 0;
                if ( !stat ) {
                    NEXT(l) = d; d = l;
                    d = nd_reconstruct(1,d);
                    goto again;
                }
            }
#endif
            sugar = SG(l);
            if ( DP_Print ) fprintf(asir_out,"%d",sugar);
        }
        stat = nd_sp(m,0,l,&h);
        if ( !stat ) {
            NEXT(l) = d; d = l;
            d = nd_reconstruct(1,d);
            goto again;
        }
#if USE_GEOBUCKET
        stat = nd_nf_pbucket(m,h,nd_ps,!Top,&nf);
#else
        stat = nd_nf(m,0,h,nd_ps,!Top,0,&nf);
#endif
        if ( !stat ) {
            NEXT(l) = d; d = l;
            d = nd_reconstruct(1,d);
            goto again;
        } else if ( nf ) {
            if ( nd_demand ) {
                nfqv = ndv_load(nd_psn);
                nfq = ndvtond(0,nfqv);
            } else
                nfq = 0;
            if ( !nfq ) {
                if ( !nd_sp(0,1,l,&h) || !nd_nf(0,0,h,nd_ps_trace,!Top,0,&nfq) ) {
                    NEXT(l) = d; d = l;
                    d = nd_reconstruct(1,d);
                    goto again;
                }
            }
            if ( nfq ) {
                /* m|HC(nfq) => failure */
                if ( nd_vc ) {
                    nd_subst_vector(nd_vc,HCP(nfq),nd_subst,&hc); q = (Q)hc;
                } else
                    q = HCQ(nfq);
                if ( !rem(NM(q),m) ) return 0;

                if ( DP_Print ) { printf("+"); fflush(stdout); }
                hnfq = HCU(nfq);
                if ( nd_nalg ) {
                    /* m|DN(HC(nf)^(-1)) => failure */
                    get_eg(&egm0);
                    if ( !nd_monic(m,&nfq) ) return 0;
                    get_eg(&egm1); add_eg(&eg_monic,&egm0,&egm1);
                    nd_removecont(0,nfq); nfqv = ndtondv(0,nfq); nd_free(nfq);
                    nfv = ndv_dup(0,nfqv); ndv_mod(m,nfv); nd_free(nf);
                } else {
                    nd_removecont(0,nfq); nfqv = ndtondv(0,nfq); nd_free(nfq);
                    nd_removecont(m,nf); nfv = ndtondv(m,nf); nd_free(nf);
                }
                if ( GenTrace ) {
				   cont = ndc_div(0,hnfq,HCU(nfqv));
				   if ( !UNIQ(cont) ) {
                       t = mknode(4,0,0,0,cont);
                       MKLIST(list,t); MKNODE(t,list,nd_tracelist);
					   nd_tracelist = t;
				   }
                }
                nh = ndv_newps(0,nfv,nfqv);
                if ( ishomo && ++diag_count == diag_period ) {
                    diag_count = 0;
                    if ( DP_Print > 2 ) fprintf(asir_out,"|");
                    stat = do_diagonalize_trace(sugar,m);
                    if ( DP_Print > 2 ) fprintf(asir_out,"|");
                    if ( !stat ) {
                        NEXT(l) = d; d = l;
                        d = nd_reconstruct(1,d);
                        goto again;
                    }
                }
                d = update_pairs(d,g,nh,0);
                g = update_base(g,nh);
            } else {
                if ( DP_Print ) { printf("*"); fflush(stdout); }
            }
        } else {
            if ( DP_Print ) { printf("."); fflush(stdout); }
        }
        FREENDP(l);
    }
    if ( nd_nalg ) {
        print_eg("monic",&eg_monic);
        print_eg("invdalg",&eg_invdalg);
        print_eg("le",&eg_le);
    }
	conv_ilist(nd_demand,1,g,indp);
    if ( DP_Print ) { printf("nd_gb_trace done.\n"); fflush(stdout); }
    return g;
}

int ndv_compare(NDV *p1,NDV *p2)
{
    return DL_COMPARE(HDL(*p1),HDL(*p2));
}

int ndv_compare_rev(NDV *p1,NDV *p2)
{
    return -DL_COMPARE(HDL(*p1),HDL(*p2));
}

int ndvi_compare(NDVI p1,NDVI p2)
{
    return DL_COMPARE(HDL(p1->p),HDL(p2->p));
}

int ndvi_compare_rev(NDVI p1,NDVI p2)
{
    return -DL_COMPARE(HDL(p1->p),HDL(p2->p));
}

NODE ndv_reduceall(int m,NODE f)
{
    int i,j,n,stat;
    ND nf,g,head;
    NODE t,a0,a;
    union oNDC dn;
    Q q,num,den;
    NODE node;
	LIST l;
	Q iq,jq;
    int *perm;
    union oNDC hc;
    P cont,cont1;

    n = length(f);
    ndv_setup(m,0,f,0,1);
	perm = (int *)MALLOC(n*sizeof(int));
	if ( GenTrace ) {
	    for ( t = nd_tracelist, i = 0; i < n; i++, t = NEXT(t) )
		    perm[i] = QTOS((Q)ARG1(BDY((LIST)BDY(t))));
	}
    for ( i = 0; i < n; ) {
        if ( GenTrace ) {
            /* Trace = [1,index,1,1] */
            STOQ(i,iq); node = mknode(4,ONE,iq,ONE,ONE);
            MKLIST(l,node); MKNODE(nd_tracelist,l,0);
        }
        g = ndvtond(m,nd_ps[i]);
        g = nd_separate_head(g,&head);
        stat = nd_nf(m,head,g,nd_ps,1,0,&nf);
        if ( !stat )
            nd_reconstruct(0,0);
        else {
            if ( DP_Print ) { printf("."); fflush(stdout); }
            ndv_free(nd_ps[i]);
            hc = HCU(nf); nd_removecont(m,nf);
            if ( GenTrace ) {
				for ( t = nd_tracelist; t; t = NEXT(t) ) {
                    jq = ARG1(BDY((LIST)BDY(t))); j = QTOS(jq);
                    STOQ(perm[j],jq); ARG1(BDY((LIST)BDY(t))) = jq;
                }
                cont = ndc_div(m,hc,HCU(nf));
                finalize_tracelist(perm[i],cont);
            }
            nd_ps[i] = ndtondv(m,nf); nd_free(nf);
            nd_bound[i] = ndv_compute_bound(nd_ps[i]);
            i++;
        }
    }
    if ( DP_Print ) { printf("\n"); }
    for ( a0 = 0, i = 0; i < n; i++ ) {
        NEXTNODE(a0,a);
		if ( !GenTrace ) BDY(a) = (pointer)nd_ps[i];
		else {
			for ( j = 0; j < n; j++ ) if ( perm[j] == i ) break;
			BDY(a) = (pointer)nd_ps[j];
		}
    }
    NEXT(a) = 0;
    return a0;
}

ND_pairs update_pairs( ND_pairs d, NODE /* of index */ g, int t, int gensyz)
{
    ND_pairs d1,nd,cur,head,prev,remove;

    if ( !g ) return d;
	/* for testing */
	if ( gensyz && GenSyz == 2 ) {
    	d1 = nd_newpairs(g,t);
    	if ( !d )
       	 return d1;
    	else {
       	 nd = d;
       	 while ( NEXT(nd) ) nd = NEXT(nd);
       	 NEXT(nd) = d1;
       	 return d;
    	}
	}
    d = crit_B(d,t);
    d1 = nd_newpairs(g,t);
    d1 = crit_M(d1);
    d1 = crit_F(d1);
    if ( gensyz || do_weyl )
        head = d1;
    else {
        prev = 0; cur = head = d1;
        while ( cur ) {
            if ( crit_2( cur->i1,cur->i2 ) ) {
                remove = cur;
                if ( !prev ) head = cur = NEXT(cur);
                else cur = NEXT(prev) = NEXT(cur);
                FREENDP(remove);
            } else {
                prev = cur; cur = NEXT(cur);
            }
        }
    }
    if ( !d )
        return head;
    else {
        nd = d;
        while ( NEXT(nd) ) nd = NEXT(nd);
        NEXT(nd) = head;
        return d;
    }
}


ND_pairs nd_newpairs( NODE g, int t )
{
    NODE h;
    UINT *dl;
    int ts,s;
    ND_pairs r,r0;

    dl = DL(nd_psh[t]);
    ts = SG(nd_psh[t]) - TD(dl);
    for ( r0 = 0, h = g; h; h = NEXT(h) ) {
        if ( nd_module && (MPOS(DL(nd_psh[(long)BDY(h)])) != MPOS(dl)) )
                continue;
        NEXTND_pairs(r0,r);
        r->i1 = (long)BDY(h);
        r->i2 = t;
        ndl_lcm(DL(nd_psh[r->i1]),dl,r->lcm);
        s = SG(nd_psh[r->i1])-TD(DL(nd_psh[r->i1]));
        SG(r) = MAX(s,ts) + TD(LCM(r));
    }
    if ( r0 ) NEXT(r) = 0;
    return r0;
}

/* kokokara */

ND_pairs crit_B( ND_pairs d, int s )
{
    ND_pairs cur,head,prev,remove;
    UINT *t,*tl,*lcm;
    int td,tdl;

    if ( !d ) return 0;
    t = DL(nd_psh[s]);
    prev = 0;
    head = cur = d;
    lcm = (UINT *)ALLOCA(nd_wpd*sizeof(UINT));
    while ( cur ) {
        tl = cur->lcm;
        if ( ndl_reducible(tl,t) ) {
            ndl_lcm(DL(nd_psh[cur->i1]),t,lcm);
            if ( !ndl_equal(lcm,tl) ) {
                ndl_lcm(DL(nd_psh[cur->i2]),t,lcm);
                if (!ndl_equal(lcm,tl)) {
                    remove = cur;
                    if ( !prev ) {
                        head = cur = NEXT(cur);
                    } else {
                        cur = NEXT(prev) = NEXT(cur);
                    }
                    FREENDP(remove);
                } else {
                    prev = cur; cur = NEXT(cur);
                }
            } else {
                    prev = cur; cur = NEXT(cur);
            }
        } else {
            prev = cur; cur = NEXT(cur);
        }
    }
    return head;
}

ND_pairs crit_M( ND_pairs d1 )
{
    ND_pairs e,d2,d3,dd,p;
    UINT *id,*jd;

    if ( !d1 ) return d1;
    for ( dd = 0, e = d1; e; e = d3 ) {
        if ( !(d2 = NEXT(e)) ) {
            NEXT(e) = dd;
            return e;
        }
        id = LCM(e);
        for ( d3 = 0; d2; d2 = p ) {
            p = NEXT(d2);
            jd = LCM(d2);
            if ( ndl_equal(jd,id) )
                ;
            else if ( TD(jd) > TD(id) )
                if ( ndl_reducible(jd,id) ) continue;
                else ;
            else if ( ndl_reducible(id,jd) ) goto delit;
            NEXT(d2) = d3;
            d3 = d2;
        }
        NEXT(e) = dd;
        dd = e;
        continue;
        /**/
    delit:    NEXT(d2) = d3;
        d3 = d2;
        for ( ; p; p = d2 ) {
            d2 = NEXT(p);
            NEXT(p) = d3;
            d3 = p;
        }
        FREENDP(e);
    }
    return dd;
}

ND_pairs crit_F( ND_pairs d1 )
{
    ND_pairs rest, head,remove;
    ND_pairs last, p, r, w;
    int s;

    if ( !d1 ) return d1;
    for ( head = last = 0, p = d1; NEXT(p); ) {
        r = w = equivalent_pairs(p,&rest);
        s = SG(r);
        w = NEXT(w);
        while ( w ) {
            if ( crit_2(w->i1,w->i2) ) {
                r = w;
                w = NEXT(w);
                while ( w ) {
                    remove = w;
                    w = NEXT(w);
                    FREENDP(remove);
                }
                break;
            } else if ( SG(w) < s ) {
                FREENDP(r);
                r = w;
                s = SG(r);
                w = NEXT(w);
            } else {
                remove = w;
                w = NEXT(w);
                FREENDP(remove);
            }
        }
        if ( last ) NEXT(last) = r;
        else head = r;
        NEXT(last = r) = 0;
        p = rest;
        if ( !p ) return head;
    }
    if ( !last ) return p;
    NEXT(last) = p;
    return head;
}

int crit_2( int dp1, int dp2 )
{
    return ndl_disjoint(DL(nd_psh[dp1]),DL(nd_psh[dp2]));
}

ND_pairs equivalent_pairs( ND_pairs d1, ND_pairs *prest )
{
    ND_pairs w,p,r,s;
    UINT *d;

    w = d1;
    d = LCM(w);
    s = NEXT(w);
    NEXT(w) = 0;
    for ( r = 0; s; s = p ) {
        p = NEXT(s);
        if ( ndl_equal(d,LCM(s)) ) {
            NEXT(s) = w; w = s;
        } else {
            NEXT(s) = r; r = s;
        }
    }
    *prest = r;
    return w;
}

NODE update_base(NODE nd,int ndp)
{
    UINT *dl, *dln;
    NODE last, p, head;

    dl = DL(nd_psh[ndp]);
    for ( head = last = 0, p = nd; p; ) {
        dln = DL(nd_psh[(long)BDY(p)]);
        if ( ndl_reducible( dln, dl ) ) {
            p = NEXT(p);
            if ( last ) NEXT(last) = p;
        } else {
            if ( !last ) head = p;
            p = NEXT(last = p);
        }
    }
    head = append_one(head,ndp);
    return head;
}

ND_pairs nd_minp( ND_pairs d, ND_pairs *prest )
{
    ND_pairs m,ml,p,l;
    UINT *lcm;
    int s,td,len,tlen,c,c1;

    if ( !(p = NEXT(m = d)) ) {
        *prest = p;
        NEXT(m) = 0;
        return m;
    }
    s = SG(m);
    if ( !NoSugar ) {
        for ( ml = 0, l = m; p; p = NEXT(l = p) )
            if ( (SG(p) < s) 
                || ((SG(p) == s) && (DL_COMPARE(LCM(p),LCM(m)) < 0)) ) {
                ml = l; m = p; s = SG(m);
            }
    } else {
        for ( ml = 0, l = m; p; p = NEXT(l = p) )
            if ( DL_COMPARE(LCM(p),LCM(m)) < 0 ) {
                ml = l; m = p; s = SG(m);
            }
    }
    if ( !ml ) *prest = NEXT(m);
    else {
        NEXT(ml) = NEXT(m);
        *prest = d;
    }
    NEXT(m) = 0;
    return m;
}

ND_pairs nd_minsugarp( ND_pairs d, ND_pairs *prest )
{
    int msugar,i;
    ND_pairs t,dm0,dm,dr0,dr;

    for ( msugar = SG(d), t = NEXT(d); t; t = NEXT(t) )
        if ( SG(t) < msugar ) msugar = SG(t);
    dm0 = 0; dr0 = 0;
    for ( i = 0, t = d; t; t = NEXT(t) )
        if ( i < nd_f4_nsp && SG(t) == msugar ) {
            if ( dm0 ) NEXT(dm) = t;
            else dm0 = t;
            dm = t;
            i++;
        } else {
            if ( dr0 ) NEXT(dr) = t;
            else dr0 = t;
            dr = t;
        }
    NEXT(dm) = 0;
    if ( dr0 ) NEXT(dr) = 0;
    *prest = dr0;
    return dm0;
}

int ndv_newps(int m,NDV a,NDV aq)
{
    int len;
    RHist r;
    NDV b;
    NODE tn;
    LIST l;
    Q iq;

    if ( nd_psn == nd_pslen ) {
        nd_pslen *= 2;
        nd_ps = (NDV *)REALLOC((char *)nd_ps,nd_pslen*sizeof(NDV));
        nd_ps_trace = (NDV *)REALLOC((char *)nd_ps_trace,nd_pslen*sizeof(NDV));
        nd_psh = (RHist *)REALLOC((char *)nd_psh,nd_pslen*sizeof(RHist));
        nd_bound = (UINT **)
            REALLOC((char *)nd_bound,nd_pslen*sizeof(UINT *));
    }
    NEWRHist(r); nd_psh[nd_psn] = r;
    nd_ps[nd_psn] = a;
    if ( aq ) {
        nd_ps_trace[nd_psn] = aq;
        register_hcf(aq);
        nd_bound[nd_psn] = ndv_compute_bound(aq);
        SG(r) = SG(aq); ndl_copy(HDL(aq),DL(r));
    } else {
        if ( !m ) register_hcf(a);
        nd_bound[nd_psn] = ndv_compute_bound(a);
        SG(r) = SG(a); ndl_copy(HDL(a),DL(r));
    }
    if ( nd_demand ) {
        if ( aq ) {
            ndv_save(nd_ps_trace[nd_psn],nd_psn);
            nd_ps_trace[nd_psn] = 0;
        } else {
            ndv_save(nd_ps[nd_psn],nd_psn);
            nd_ps[nd_psn] = 0;
        }
    }
    if ( GenTrace ) {
        /* reverse the tracelist and append it to alltracelist */
        nd_tracelist = reverse_node(nd_tracelist); MKLIST(l,nd_tracelist);
        STOQ(nd_psn,iq); tn = mknode(2,iq,l); MKLIST(l,tn);
        MKNODE(tn,l,nd_alltracelist); nd_alltracelist = tn; nd_tracelist = 0;
    }
    return nd_psn++;
}

/* nd_tracelist = [[0,index,div],...,[nd_psn-1,index,div]] */

void ndv_setup(int mod,int trace,NODE f,int dont_sort,int dont_removecont)
{
    int i,j,td,len,max;
    NODE s,s0,f0,tn;
    UINT *d;
    RHist r;
    NDVI w;
    NDV a,am;
    union oNDC hc;
    NODE node;
    P hcp;
    Q iq,jq,hcq;
    LIST l;

    nd_found = 0; nd_notfirst = 0; nd_create = 0;
    /* initialize the tracelist */
    nd_tracelist = 0;

    for ( nd_psn = 0, s = f; s; s = NEXT(s) ) if ( BDY(s) ) nd_psn++;
    w = (NDVI)ALLOCA(nd_psn*sizeof(struct oNDVI));
    for ( i = j = 0, s = f; s; s = NEXT(s), j++ ) 
        if ( BDY(s) ) { w[i].p = BDY(s); w[i].i = j; i++; }
    if ( !dont_sort ) {
        /* XXX heuristic */
        if ( !nd_ord->id && (nd_ord->ord.simple<2) )
            qsort(w,nd_psn,sizeof(struct oNDVI),
                (int (*)(const void *,const void *))ndvi_compare_rev);
        else
            qsort(w,nd_psn,sizeof(struct oNDVI),
                (int (*)(const void *,const void *))ndvi_compare);
    }
    nd_pslen = 2*nd_psn;
    nd_ps = (NDV *)MALLOC(nd_pslen*sizeof(NDV));
    nd_ps_trace = (NDV *)MALLOC(nd_pslen*sizeof(NDV));
    nd_psh = (RHist *)MALLOC(nd_pslen*sizeof(RHist));
    nd_bound = (UINT **)MALLOC(nd_pslen*sizeof(UINT *));
    nd_hcf = 0;

    if ( trace && nd_vc )
        makesubst(nd_vc,&nd_subst);
    else
        nd_subst = 0;

    if ( !nd_red )
        nd_red = (RHist *)MALLOC(REDTAB_LEN*sizeof(RHist));
    for ( i = 0; i < REDTAB_LEN; i++ ) nd_red[i] = 0;
    for ( i = 0; i < nd_psn; i++ ) {
        hc = HCU(w[i].p);
        if ( trace ) {
            a = nd_ps_trace[i] = ndv_dup(0,w[i].p);
            if ( !dont_removecont) ndv_removecont(0,a);
            register_hcf(a);
            am = nd_ps[i] = ndv_dup(mod,a);
            ndv_mod(mod,am);
            ndv_removecont(mod,am);
        } else {
            a = nd_ps[i] = ndv_dup(mod,w[i].p);
            if ( mod || !dont_removecont ) ndv_removecont(mod,a);
            if ( !mod ) register_hcf(a);
        }
        if ( GenTrace ) {
            STOQ(i,iq); STOQ(w[i].i,jq); node = mknode(3,iq,jq,ONE);
			if ( !dont_removecont )
                ARG2(node) = (pointer)ndc_div(trace?0:mod,hc,HCU(a));
            MKLIST(l,node); NEXTNODE(nd_tracelist,tn); BDY(tn) = l;
        }
        NEWRHist(r); SG(r) = HTD(a); ndl_copy(HDL(a),DL(r));
        nd_bound[i] = ndv_compute_bound(a);
        nd_psh[i] = r;
        if ( nd_demand ) {
            if ( trace ) {
                ndv_save(nd_ps_trace[i],i);
                nd_ps_trace[i] = 0;
            } else {
                ndv_save(nd_ps[i],i);
                nd_ps[i] = 0;
            }
        }
    }
    if ( GenTrace && nd_tracelist ) NEXT(tn) = 0;
}

struct order_spec *append_block(struct order_spec *spec,
    int nv,int nalg,int ord);

extern VECT current_dl_weight_vector_obj;
static VECT prev_weight_vector_obj;

void preprocess_algcoef(VL vv,VL av,struct order_spec *ord,LIST f,
    struct order_spec **ord1p,LIST *f1p,NODE *alistp)
{
    NODE alist,t,s,r0,r,arg;
    VL tv;
    P poly;
    DP d;
    Alg alpha,dp;
    DAlg inv,da,hc;
    MP m;
    int i,nvar,nalg,n;
    NumberField nf;
    LIST f1,f2;
    struct order_spec *current_spec;
    VECT obj,obj0;
    Obj tmp;

    for ( nvar = 0, tv = vv; tv; tv = NEXT(tv), nvar++);
    for ( nalg = 0, tv = av; tv; tv = NEXT(tv), nalg++);

    for ( alist = 0, tv = av; tv; tv = NEXT(tv) ) {
        NEXTNODE(alist,t); MKV(tv->v,poly); 
        MKAlg(poly,alpha); BDY(t) = (pointer)alpha;
        tv->v = tv->v->priv;
    }
    NEXT(t) = 0;

    /* simplification, making polynomials monic */
    setfield_dalg(alist);
    obj_algtodalg(f,&f1);
    for ( t = BDY(f); t; t = NEXT(t) ) {
        initd(ord); ptod(vv,vv,(P)BDY(t),&d);            
        hc = (DAlg)BDY(d)->c;
        if ( NID(hc) == N_DA ) {
            invdalg(hc,&inv);
            for ( m = BDY(d); m; m = NEXT(m) ) {
                muldalg(inv,(DAlg)m->c,&da); m->c = (P)da;
            }
        }
        initd(ord); dtop(vv,vv,d,&poly); BDY(f) = (pointer)poly;
    }
    obj_dalgtoalg(f1,&f);

    /* append alg vars to the var list */
    for ( tv = vv; NEXT(tv); tv = NEXT(tv) );
    NEXT(tv) = av;

    /* append a block to ord */
    *ord1p = append_block(ord,nvar,nalg,2);

    /* create generator list */
    nf = get_numberfield();
    for ( i = nalg-1, t = BDY(f); i >= 0; i-- ) {
        MKAlg(nf->defpoly[i],dp);
        MKNODE(s,dp,t); t = s;
    }
    MKLIST(f1,t);
    *alistp = alist;
    algobjtorat(f1,f1p);

    /* creating a new weight vector */
    prev_weight_vector_obj = obj0 = current_dl_weight_vector_obj;
    n = nvar+nalg+1;
    MKVECT(obj,n);
    if ( obj0 && obj0->len == nvar )
        for ( i = 0; i < nvar; i++ ) BDY(obj)[i] = BDY(obj0)[i];
    else
        for ( i = 0; i < nvar; i++ ) BDY(obj)[i] = (pointer)ONE;
    for ( i = 0; i < nalg; i++ ) BDY(obj)[i+nvar] = 0;
    BDY(obj)[n-1] = (pointer)ONE;
    arg = mknode(1,obj);
    Pdp_set_weight(arg,&tmp);
}

NODE postprocess_algcoef(VL av,NODE alist,NODE r)
{
    NODE s,t,u0,u;
    P p;
    VL tv;
    Obj obj,tmp;
    NODE arg;

    u0 = 0;
    for ( t = r; t; t = NEXT(t) ) {
        p = (P)BDY(t);
        for ( tv = av, s = alist; tv; tv = NEXT(tv), s = NEXT(s) ) {
            substr(CO,0,(Obj)p,tv->v,(Obj)BDY(s),&obj); p = (P)obj;
        }
        if ( OID(p) == O_P || (OID(p) == O_N && NID((Num)p) != N_A) ) {
            NEXTNODE(u0,u);
            BDY(u) = (pointer)p;
        }
    }    
    arg = mknode(1,prev_weight_vector_obj);
    Pdp_set_weight(arg,&tmp);

    return u0;
}

void nd_gr(LIST f,LIST v,int m,int f4,struct order_spec *ord,LIST *rp)
{
    VL tv,fv,vv,vc,av;
    NODE fd,fd0,r,r0,t,x,s,xx,alist;
    int e,max,nvar,i;
    NDV b;
    int ishomo,nalg,mrank,trank;
    Alg alpha,dp;
    P p,zp;
    Q dmy;
    LIST f1,f2,zpl;
    Obj obj;
    NumberField nf;
    struct order_spec *ord1;
    NODE tr,tl1,tl2,tl3,tl4;
    LIST l1,l2,l3,l4,l5;
	int j;
	Q jq;
    int *perm;
    EPOS oepos;
    int obpe,oadv,ompos;

    nd_module = 0;
    if ( !m && Demand ) nd_demand = 1;
    else nd_demand = 0;

    if ( DP_Multiple )
        nd_scale = ((double)DP_Multiple)/(double)(Denominator?Denominator:1);
#if 0
    ndv_alloc = 0;
#endif
    get_vars((Obj)f,&fv); pltovl(v,&vv); vlminus(fv,vv,&nd_vc);
    for ( nvar = 0, tv = vv; tv; tv = NEXT(tv), nvar++ );
    switch ( ord->id ) {
        case 1:
            if ( ord->nv != nvar )
                error("nd_{gr,f4} : invalid order specification");
            break;
        default:
            break;
    }
    nd_nalg = 0;
    av = 0;
    if ( !m ) {
        get_algtree((Obj)f,&av);
        for ( nalg = 0, tv = av; tv; tv = NEXT(tv), nalg++ );
        nd_ntrans = nvar;
        nd_nalg = nalg;
        /* #i -> t#i */
        if ( nalg ) {
            preprocess_algcoef(vv,av,ord,f,&ord1,&f1,&alist);
            ord = ord1;
            f = f1;
        }
        nvar += nalg;
    }
    nd_init_ord(ord);
    mrank = 0;
    for ( t = BDY(f), max = 0; t; t = NEXT(t) )
        for ( tv = vv; tv; tv = NEXT(tv) ) {
            if ( nd_module ) {
                s = BDY((LIST)BDY(t));
                trank = length(s);
                mrank = MAX(mrank,trank);
                for ( ; s; s = NEXT(s) ) {
                    e = getdeg(tv->v,(P)BDY(s));
                    max = MAX(e,max);
                }
            } else {
                e = getdeg(tv->v,(P)BDY(t));
                max = MAX(e,max);
            }
        }
    nd_setup_parameters(nvar,max);
    obpe = nd_bpe; oadv = nmv_adv; oepos = nd_epos; ompos = nd_mpos;
    ishomo = 1;
    for ( fd0 = 0, t = BDY(f); t; t = NEXT(t) ) {
        if ( nd_module ) {
			if ( !m && !GenTrace ) pltozpl((LIST)BDY(t),&dmy,&zpl);
			else zpl = (LIST)BDY(t);
            b = (pointer)pltondv(CO,vv,zpl);
        } else {
			if ( !m && !GenTrace ) ptozp((P)BDY(t),1,&dmy,&zp);
			else zp = (P)BDY(t);
            b = (pointer)ptondv(CO,vv,zp);
        }
        if ( ishomo )
            ishomo = ishomo && ndv_ishomo(b);
        if ( m ) ndv_mod(m,b);
        if ( b ) { NEXTNODE(fd0,fd); BDY(fd) = (pointer)b; }
    }
    if ( fd0 ) NEXT(fd) = 0;
    ndv_setup(m,0,fd0,0,0);
    if ( GenTrace ) {
        MKLIST(l1,nd_tracelist); MKNODE(nd_alltracelist,l1,0);
    }
    x = f4?nd_f4(m,&perm):nd_gb(m,ishomo,0,0,&perm);
    nd_demand = 0;
    x = ndv_reducebase(x,perm);
    if ( GenTrace ) { tl1 = nd_alltracelist; nd_alltracelist = 0; }
    x = ndv_reduceall(m,x);
    if ( GenTrace ) { 
        tl2 = nd_alltracelist; nd_alltracelist = 0;
        ndv_check_membership(m,fd0,obpe,oadv,oepos,x);
        if ( GenTrace ) { 
            tl3 = nd_alltracelist; nd_alltracelist = 0; 
        } else tl3 = 0;
        nd_gb(m,0,1,GenSyz?1:0,0)!=0;
        if ( GenTrace && GenSyz ) { 
            tl4 = nd_alltracelist; nd_alltracelist = 0; 
        } else tl4 = 0;
    }
    for ( r0 = 0, t = x; t; t = NEXT(t) ) {
        NEXTNODE(r0,r); 
    if ( nd_module ) BDY(r) = ndvtopl(m,CO,vv,BDY(t),mrank);
        else BDY(r) = ndvtop(m,CO,vv,BDY(t));
    }
    if ( r0 ) NEXT(r) = 0;
    if ( nalg )
        r0 = postprocess_algcoef(av,alist,r0);
    MKLIST(*rp,r0);
    if ( GenTrace ) {
        tl1 = reverse_node(tl1); tl2 = reverse_node(tl2);
	tl3 = reverse_node(tl3);
		/* tl2 = [[i,[[*,j,*,*],...]],...] */
        for ( t = tl2; t; t = NEXT(t) ) {
			/* s = [i,[*,j,*,*],...] */
            s = BDY((LIST)BDY(t));
            j = perm[QTOS((Q)ARG0(s))]; STOQ(j,jq); ARG0(s) = (pointer)jq;
			for ( s = BDY((LIST)ARG1(s)); s; s = NEXT(s) ) {
                j = perm[QTOS((Q)ARG1(BDY((LIST)BDY(s))))]; STOQ(j,jq); 
				ARG1(BDY((LIST)BDY(s))) = (pointer)jq;
            }
		}
		for ( j = length(x)-1, t = 0; j >= 0; j-- ) {
		    STOQ(perm[j],jq); MKNODE(s,jq,t); t = s;
		}
       MKLIST(l1,tl1); MKLIST(l2,tl2); MKLIST(l3,t); MKLIST(l4,tl3);
       MKLIST(l5,tl4);
      tr = mknode(7,*rp,0,l1,l2,l3,l4,l5); MKLIST(*rp,tr);
    }
#if 0
    fprintf(asir_out,"ndv_alloc=%d\n",ndv_alloc);
#endif
}

void nd_gr_postproc(LIST f,LIST v,int m,struct order_spec *ord,int do_check,LIST *rp)
{
    VL tv,fv,vv,vc,av;
    NODE fd,fd0,r,r0,t,x,s,xx,alist;
    int e,max,nvar,i;
    NDV b;
    int ishomo,nalg;
    Alg alpha,dp;
    P p,zp;
    Q dmy;
    LIST f1,f2;
    Obj obj;
    NumberField nf;
    struct order_spec *ord1;
    int *perm;

    get_vars((Obj)f,&fv); pltovl(v,&vv); vlminus(fv,vv,&nd_vc);
    for ( nvar = 0, tv = vv; tv; tv = NEXT(tv), nvar++ );
    switch ( ord->id ) {
        case 1:
            if ( ord->nv != nvar )
                error("nd_check : invalid order specification");
            break;
        default:
            break;
    }
    nd_nalg = 0;
    av = 0;
    if ( !m ) {
        get_algtree((Obj)f,&av);
        for ( nalg = 0, tv = av; tv; tv = NEXT(tv), nalg++ );
        nd_ntrans = nvar;
        nd_nalg = nalg;
        /* #i -> t#i */
        if ( nalg ) {
            preprocess_algcoef(vv,av,ord,f,&ord1,&f1,&alist);
            ord = ord1;
            f = f1;
        }
        nvar += nalg;
    }
    nd_init_ord(ord);
    for ( t = BDY(f), max = 0; t; t = NEXT(t) )
        for ( tv = vv; tv; tv = NEXT(tv) ) {
            e = getdeg(tv->v,(P)BDY(t));
            max = MAX(e,max);
        }
    nd_setup_parameters(nvar,max);
    ishomo = 1;
    for ( fd0 = 0, t = BDY(f); t; t = NEXT(t) ) {
        ptozp((P)BDY(t),1,&dmy,&zp);
        b = (pointer)ptondv(CO,vv,zp);
        if ( ishomo )
            ishomo = ishomo && ndv_ishomo(b);
        if ( m ) ndv_mod(m,b);
        if ( b ) { NEXTNODE(fd0,fd); BDY(fd) = (pointer)b; }
    }
    if ( fd0 ) NEXT(fd) = 0;
    ndv_setup(m,0,fd0,0,1);
    for ( x = 0, i = 0; i < nd_psn; i++ )
        x = update_base(x,i);
    if ( do_check ) {
        x = nd_gb(m,ishomo,1,0,&perm);
        if ( !x ) {
            *rp = 0;
            return;
        }
    } else {
        for ( t = x; t; t = NEXT(t) )
            BDY(t) = (pointer)nd_ps[(long)BDY(t)];
    }
    x = ndv_reducebase(x,perm);
    x = ndv_reduceall(m,x);
    for ( r0 = 0, t = x; t; t = NEXT(t) ) {
        NEXTNODE(r0,r); 
        BDY(r) = ndvtop(m,CO,vv,BDY(t));
    }
    if ( r0 ) NEXT(r) = 0;
    if ( nalg )
        r0 = postprocess_algcoef(av,alist,r0);
    MKLIST(*rp,r0);
}

void nd_gr_trace(LIST f,LIST v,int trace,int homo,int f4,struct order_spec *ord,LIST *rp)
{
    VL tv,fv,vv,vc,av;
    NODE fd,fd0,in0,in,r,r0,t,s,cand,alist;
    int m,nocheck,nvar,mindex,e,max;
    NDV c;
    NMV a;
    P p,zp;
    Q dmy;
    EPOS oepos;
    int obpe,oadv,wmax,i,len,cbpe,ishomo,nalg,mrank,trank,ompos;
    Alg alpha,dp;
    P poly;
    LIST f1,f2,zpl;
    Obj obj;
    NumberField nf;
    struct order_spec *ord1;
    struct oEGT eg_check,eg0,eg1;
    NODE tr,tl1,tl2,tl3,tl4;
    LIST l1,l2,l3,l4,l5;
    int *perm;
    int j,ret;
    Q jq;

    nd_module = 0;
    if ( DP_Multiple )
        nd_scale = ((double)DP_Multiple)/(double)(Denominator?Denominator:1);

    get_vars((Obj)f,&fv); pltovl(v,&vv); vlminus(fv,vv,&nd_vc);
    for ( nvar = 0, tv = vv; tv; tv = NEXT(tv), nvar++ );
    switch ( ord->id ) {
        case 1:
            if ( ord->nv != nvar )
                error("nd_gr_trace : invalid order specification");
            break;
        default:
            break;
    }

    get_algtree((Obj)f,&av);
    for ( nalg = 0, tv = av; tv; tv = NEXT(tv), nalg++ );
    nd_ntrans = nvar;
    nd_nalg = nalg;
    /* #i -> t#i */
    if ( nalg ) {
        preprocess_algcoef(vv,av,ord,f,&ord1,&f1,&alist);
        ord = ord1;
        f = f1;
    }
    nvar += nalg;

    nocheck = 0;
    mindex = 0;

    if ( Demand ) nd_demand = 1;
    else nd_demand = 0;

    /* setup modulus */
    if ( trace < 0 ) {
        trace = -trace;
        nocheck = 1;
    }
    m = trace > 1 ? trace : get_lprime(mindex);
    nd_init_ord(ord);
    mrank = 0;
    for ( t = BDY(f), max = 0; t; t = NEXT(t) )
        for ( tv = vv; tv; tv = NEXT(tv) ) {
            if ( nd_module ) {
                s = BDY((LIST)BDY(t));
                trank = length(s);
                mrank = MAX(mrank,trank);
                for ( ; s; s = NEXT(s) ) {
                    e = getdeg(tv->v,(P)BDY(s));
                    max = MAX(e,max);
                }
            } else {
                e = getdeg(tv->v,(P)BDY(t));
                max = MAX(e,max);
            }
        }
    nd_setup_parameters(nvar,max);
    obpe = nd_bpe; oadv = nmv_adv; oepos = nd_epos; ompos = nd_mpos;
    ishomo = 1;
    for ( in0 = 0, fd0 = 0, t = BDY(f); t; t = NEXT(t) ) {
        if ( nd_module ) {
			if ( !GenTrace ) pltozpl((LIST)BDY(t),&dmy,&zpl);
			else zpl = (LIST)BDY(t);
            c = (pointer)pltondv(CO,vv,zpl);
        } else {
			if ( !GenTrace ) ptozp((P)BDY(t),1,&dmy,&zp);
			else zp = (P)BDY(t);
            c = (pointer)ptondv(CO,vv,zp);
        }
        if ( ishomo )
            ishomo = ishomo && ndv_ishomo(c);
        if ( c ) { 
            NEXTNODE(in0,in); BDY(in) = (pointer)c;
            NEXTNODE(fd0,fd); BDY(fd) = (pointer)ndv_dup(0,c);
        }
    }
    if ( in0 ) NEXT(in) = 0;
    if ( fd0 ) NEXT(fd) = 0;
    if ( !ishomo && homo ) {
        for ( t = in0, wmax = max; t; t = NEXT(t) ) {
            c = (NDV)BDY(t); len = LEN(c);
            for ( a = BDY(c), i = 0; i < len; i++, NMV_ADV(a) )
                wmax = MAX(TD(DL(a)),wmax);
        }
        homogenize_order(ord,nvar,&ord1);
        nd_init_ord(ord1);
        nd_setup_parameters(nvar+1,wmax);
        for ( t = fd0; t; t = NEXT(t) )
            ndv_homogenize((NDV)BDY(t),obpe,oadv,oepos,ompos);
    }
    while ( 1 ) {
        if ( Demand )
            nd_demand = 1;
        ndv_setup(m,1,fd0,0,0);
        if ( GenTrace ) {
            MKLIST(l1,nd_tracelist); MKNODE(nd_alltracelist,l1,0);
        }
        cand = f4?nd_f4_trace(m,&perm):nd_gb_trace(m,ishomo || homo,&perm);
        if ( !cand ) {
            /* failure */
            if ( trace > 1 ) { *rp = 0; return; }
            else m = get_lprime(++mindex);
            continue;
        }
        if ( !ishomo && homo ) {
            /* dehomogenization */
            for ( t = cand; t; t = NEXT(t) ) ndv_dehomogenize((NDV)BDY(t),ord);
            nd_init_ord(ord);
            nd_setup_parameters(nvar,0);
        }
        nd_demand = 0;
        cand = ndv_reducebase(cand,perm);
        if ( GenTrace ) { tl1 = nd_alltracelist; nd_alltracelist = 0; }
        cand = ndv_reduceall(0,cand);
        cbpe = nd_bpe;
        if ( GenTrace ) { tl2 = nd_alltracelist; nd_alltracelist = 0; }
        if ( nocheck )
            break;
        get_eg(&eg0);
        if ( ret = ndv_check_membership(0,in0,obpe,oadv,oepos,cand) ) {
            if ( GenTrace ) { 
			    tl3 = nd_alltracelist; nd_alltracelist = 0; 
		    } else tl3 = 0;
            /* gbcheck : cand is a GB of Id(cand) ? */
            ret = nd_gb(0,0,1,GenSyz?1:0,0)!=0;
            if ( GenTrace && GenSyz ) { 
			    tl4 = nd_alltracelist; nd_alltracelist = 0; 
		    } else tl4 = 0;
		}
		if ( ret ) break;
        else if ( trace > 1 ) {
            /* failure */
            *rp = 0; return;    
        } else {
            /* try the next modulus */
            m = get_lprime(++mindex);
            /* reset the parameters */
            if ( !ishomo && homo ) {
                nd_init_ord(ord1);
                nd_setup_parameters(nvar+1,wmax);
            } else {
                nd_init_ord(ord);
                nd_setup_parameters(nvar,max);
            }
        }
    }
    get_eg(&eg1); init_eg(&eg_check); add_eg(&eg_check,&eg0,&eg1);
    if ( DP_Print )
        fprintf(asir_out,"check=%fsec\n",eg_check.exectime+eg_check.gctime);
    /* dp->p */
    nd_bpe = cbpe;
    nd_setup_parameters(nd_nvar,0);
    for ( r = cand; r; r = NEXT(r) ) {
    if ( nd_module ) BDY(r) = ndvtopl(0,CO,vv,BDY(r),mrank);
        else BDY(r) = (pointer)ndvtop(0,CO,vv,BDY(r));
    }
    if ( nalg )
        cand = postprocess_algcoef(av,alist,cand);
    MKLIST(*rp,cand);
    if ( GenTrace ) {
        tl1 = reverse_node(tl1); tl2 = reverse_node(tl2);
		tl3 = reverse_node(tl3);
		/* tl2 = [[i,[[*,j,*,*],...]],...] */
        for ( t = tl2; t; t = NEXT(t) ) {
			/* s = [i,[*,j,*,*],...] */
            s = BDY((LIST)BDY(t));
            j = perm[QTOS((Q)ARG0(s))]; STOQ(j,jq); ARG0(s) = (pointer)jq;
			for ( s = BDY((LIST)ARG1(s)); s; s = NEXT(s) ) {
                j = perm[QTOS((Q)ARG1(BDY((LIST)BDY(s))))]; STOQ(j,jq); 
				ARG1(BDY((LIST)BDY(s))) = (pointer)jq;
            }
		}
		for ( j = length(cand)-1, t = 0; j >= 0; j-- ) {
		    STOQ(perm[j],jq); MKNODE(s,jq,t); t = s;
		}
        MKLIST(l1,tl1); MKLIST(l2,tl2); MKLIST(l3,t); MKLIST(l4,tl3);
		MKLIST(l5,tl4);
        tr = mknode(7,*rp,(!ishomo&&homo)?ONE:0,l1,l2,l3,l4,l5); MKLIST(*rp,tr);
    }
}

/* XXX : module element is not considered  */

void dltondl(int n,DL dl,UINT *r)
{
    UINT *d;
    int i,j,l,s,ord_l;
    struct order_pair *op;

    d = dl->d;
    for ( i = 0; i < nd_wpd; i++ ) r[i] = 0;
    if ( nd_blockmask ) {
        l = nd_blockmask->n;
        op = nd_blockmask->order_pair;
        for ( j = 0, s = 0; j < l; j++ ) {
            ord_l = op[j].length;
            for ( i = 0; i < ord_l; i++, s++ ) PUT_EXP(r,s,d[s]);
        }
        TD(r) = ndl_weight(r);
        ndl_weight_mask(r);
    } else {
        for ( i = 0; i < n; i++ ) PUT_EXP(r,i,d[i]);
        TD(r) = ndl_weight(r);
    }
}

DL ndltodl(int n,UINT *ndl)
{
    DL dl;
    int *d;
    int i,j,l,s,ord_l;
    struct order_pair *op;

    NEWDL(dl,n);
    dl->td = TD(ndl);
    d = dl->d;
    if ( nd_blockmask ) {
        l = nd_blockmask->n;
        op = nd_blockmask->order_pair;
        for ( j = 0, s = 0; j < l; j++ ) {
            ord_l = op[j].length;
            for ( i = 0; i < ord_l; i++, s++ ) d[s] = GET_EXP(ndl,s);
        }
    } else {
        for ( i = 0; i < n; i++ ) d[i] = GET_EXP(ndl,i);
    }
    return dl;
}

void nmtodp(int mod,NM m,DP *r)
{
    DP dp;
    MP mr;

    NEWMP(mr); 
    mr->dl = ndltodl(nd_nvar,DL(m));
    mr->c = ndctop(mod,m->c);
    NEXT(mr) = 0; MKDP(nd_nvar,mr,dp); dp->sugar = mr->dl->td;
    *r = dp;
}

void ndl_print(UINT *dl)
{
    int n;
    int i,j,l,ord_l,s,s0;
    struct order_pair *op;

    n = nd_nvar;
    printf("<<");
    if ( nd_blockmask ) {
        l = nd_blockmask->n;
        op = nd_blockmask->order_pair;
        for ( j = 0, s = s0 = 0; j < l; j++ ) {
            ord_l = op[j].length;
            for ( i = 0; i < ord_l; i++, s++ )
                printf(s==n-1?"%d":"%d,",GET_EXP(dl,s));
        }
    } else {
        for ( i = 0; i < n; i++ ) printf(i==n-1?"%d":"%d,",GET_EXP(dl,i));
    }
    printf(">>");
    if ( MPOS(dl) )
        printf("*e%d",MPOS(dl));
}

void nd_print(ND p)
{
    NM m;

    if ( !p )
        printf("0\n");
    else {
        for ( m = BDY(p); m; m = NEXT(m) ) {
            if ( CM(m) & 0x80000000 ) printf("+@_%d*",IFTOF(CM(m)));
            else printf("+%d*",CM(m));
            ndl_print(DL(m));
        }
        printf("\n");
    }
}

void nd_print_q(ND p)
{
    NM m;

    if ( !p )
        printf("0\n");
    else {
        for ( m = BDY(p); m; m = NEXT(m) ) {
            printf("+");
            printexpr(CO,(Obj)CQ(m));
            printf("*");
            ndl_print(DL(m));
        }
        printf("\n");
    }
}

void ndp_print(ND_pairs d)
{
    ND_pairs t;

    for ( t = d; t; t = NEXT(t) ) printf("%d,%d ",t->i1,t->i2);
    printf("\n");
}

void nd_removecont(int mod,ND p)
{
    int i,n;
    Q *w;
    Q dvr,t;
    NM m;
    struct oVECT v;
    N q,r;

    if ( mod == -1 ) nd_mul_c(mod,p,_invsf(HCM(p)));
    else if ( mod ) nd_mul_c(mod,p,invm(HCM(p),mod));
    else {
        for ( m = BDY(p), n = 0; m; m = NEXT(m), n++ );
        w = (Q *)ALLOCA(n*sizeof(Q));
        v.len = n;
        v.body = (pointer *)w;
        for ( m = BDY(p), i = 0; i < n; m = NEXT(m), i++ ) w[i] = CQ(m);
        removecont_array((P *)w,n,1);
        for ( m = BDY(p), i = 0; i < n; m = NEXT(m), i++ ) CQ(m) = w[i];    
    }
}

void nd_removecont2(ND p1,ND p2)
{
    int i,n1,n2,n;
    Q *w;
    Q dvr,t;
    NM m;
    struct oVECT v;
    N q,r;

    n1 = nd_length(p1);
    n2 = nd_length(p2);
    n = n1+n2;
    w = (Q *)ALLOCA(n*sizeof(Q));
    v.len = n;
    v.body = (pointer *)w;
    i = 0;
    if ( p1 )
        for ( m = BDY(p1); i < n1; m = NEXT(m), i++ ) w[i] = CQ(m);
    if ( p2 )
        for ( m = BDY(p2); i < n; m = NEXT(m), i++ ) w[i] = CQ(m);
    removecont_array((P *)w,n,1);
    i = 0;
    if ( p1 )
        for ( m = BDY(p1); i < n1; m = NEXT(m), i++ ) CQ(m) = w[i];    
    if ( p2 )
        for ( m = BDY(p2); i < n; m = NEXT(m), i++ ) CQ(m) = w[i];    
}

void ndv_removecont(int mod,NDV p)
{
    int i,len,all_p;
    Q *c;
    P *w;
    Q dvr,t;
    P g,cont,tp;
    NMV m;

    if ( mod == -1 )
        ndv_mul_c(mod,p,_invsf(HCM(p)));
    else if ( mod )
        ndv_mul_c(mod,p,invm(HCM(p),mod));
    else {
        len = p->len;
        w = (P *)ALLOCA(len*sizeof(P));
        c = (Q *)ALLOCA(len*sizeof(Q));
        for ( m = BDY(p), all_p = 1, i = 0; i < len; NMV_ADV(m), i++ ) {
            ptozp(CP(m),1,&c[i],&w[i]);
            all_p = all_p && !NUM(w[i]);
        }
        if ( all_p ) {
            qltozl(c,len,&dvr); nd_heu_nezgcdnpz(nd_vc,w,len,1,&g);
            mulp(nd_vc,(P)dvr,g,&cont);
            for ( m = BDY(p), i = 0; i < len; NMV_ADV(m), i++ ) {
                divsp(nd_vc,CP(m),cont,&tp); CP(m) = tp;
            }
        } else {
            sortbynm((Q *)c,len);
            qltozl((Q *)c,len,&dvr);
            for ( m = BDY(p), i = 0; i < len; NMV_ADV(m), i++ ) {
                divsp(nd_vc,CP(m),(P)dvr,&tp); CP(m) = tp;
            }
        }
    }
}

/* koko */

void ndv_homogenize(NDV p,int obpe,int oadv,EPOS oepos,int ompos)
{
    int len,i,max;
    NMV m,mr0,mr,t;

    len = p->len;
    for ( m = BDY(p), i = 0, max = 0; i < len; NMV_OADV(m), i++ )
        max = MAX(max,TD(DL(m)));
    mr0 = nmv_adv>oadv?(NMV)REALLOC(BDY(p),len*nmv_adv):BDY(p);
    m = (NMV)((char *)mr0+(len-1)*oadv);
    mr = (NMV)((char *)mr0+(len-1)*nmv_adv);
    t = (NMV)ALLOCA(nmv_adv);
    for ( i = 0; i < len; i++, NMV_OPREV(m), NMV_PREV(mr) ) {
        ndl_homogenize(DL(m),DL(t),obpe,oepos,ompos,max);
        CQ(mr) = CQ(m);
        ndl_copy(DL(t),DL(mr));
    }
    NV(p)++;
    BDY(p) = mr0;
}

void ndv_dehomogenize(NDV p,struct order_spec *ord)
{
    int i,j,adj,len,newnvar,newwpd,newadv,newexporigin,newmpos;
    int pos;
    Q *w;
    Q dvr,t;
    NMV m,r;

    len = p->len;
    newnvar = nd_nvar-1;
    newexporigin = nd_get_exporigin(ord);
    if ( nd_module ) newmpos = newexporigin-1;
    newwpd = newnvar/nd_epw+(newnvar%nd_epw?1:0)+newexporigin;
    for ( m = BDY(p), i = 0; i < len; NMV_ADV(m), i++ )
        ndl_dehomogenize(DL(m));
    if ( newwpd != nd_wpd ) {
        newadv = ROUND_FOR_ALIGN(sizeof(struct oNMV)+(newwpd-1)*sizeof(UINT));
        for ( m = r = BDY(p), i = 0; i < len; NMV_ADV(m), NDV_NADV(r), i++ ) {
            CQ(r) = CQ(m);
            if ( nd_module ) pos = MPOS(DL(m));
            for ( j = 0; j < newexporigin; j++ ) DL(r)[j] = DL(m)[j];
            adj = nd_exporigin-newexporigin;
            for ( ; j < newwpd; j++ ) DL(r)[j] = DL(m)[j+adj];
            if ( nd_module ) {
                DL(r)[newmpos] = pos;
            }
        }
    }
    NV(p)--;
}

void nd_heu_nezgcdnpz(VL vl,P *pl,int m,int full,P *pr)
{
    int i;
    P *tpl,*tpl1;
    NODE l;
    P h,gcd,t;

    tpl = (P *)ALLOCA(m*sizeof(P));
    tpl1 = (P *)ALLOCA(m*sizeof(P));
    bcopy(pl,tpl,m*sizeof(P));
    gcd = (P)ONE;
    for ( l = nd_hcf; l; l = NEXT(l) ) {
        h = (P)BDY(l);
        while ( 1 ) {
            for ( i = 0; i < m; i++ )
                if ( !divtpz(vl,tpl[i],h,&tpl1[i]) )
                    break;
            if ( i == m ) {
                bcopy(tpl1,tpl,m*sizeof(P));
                mulp(vl,gcd,h,&t); gcd = t;
            } else
                break;
        }
    }
    if ( DP_Print > 2 ){fprintf(asir_out,"[%d]",nmonop(gcd)); fflush(asir_out);}
    if ( full ) {
        heu_nezgcdnpz(vl,tpl,m,&t);
        mulp(vl,gcd,t,pr);
    } else
        *pr = gcd;
}

void removecont_array(P *p,int n,int full)
{
    int all_p,all_q,i;
    Q *c;
    P *w;
    P t,s;

    for ( all_q = 1, i = 0; i < n; i++ )
        all_q = all_q && NUM(p[i]);
    if ( all_q ) {
        removecont_array_q((Q *)p,n);
    } else {
        c = (Q *)ALLOCA(n*sizeof(Q));
        w = (P *)ALLOCA(n*sizeof(P));
        for ( i = 0; i < n; i++ ) {
            ptozp(p[i],1,&c[i],&w[i]);
        }
        removecont_array_q(c,n);
        nd_heu_nezgcdnpz(nd_vc,w,n,full,&t);
        for ( i = 0; i < n; i++ ) {
            divsp(nd_vc,w[i],t,&s); mulp(nd_vc,s,(P)c[i],&p[i]);
        }
    }
}

void removecont_array_q(Q *c,int n)
{
    struct oVECT v;
    Q d0,d1,a,u,u1,gcd;
    int i,j;
    N qn,rn,gn;
    Q *q,*r;

    q = (Q *)ALLOCA(n*sizeof(Q));
    r = (Q *)ALLOCA(n*sizeof(Q));
    v.id = O_VECT; v.len = n; v.body = (pointer *)c;
    igcdv_estimate(&v,&d0);
    for ( i = 0; i < n; i++ ) {
        divn(NM(c[i]),NM(d0),&qn,&rn);
        NTOQ(qn,SGN(c[i])*SGN(d0),q[i]);
        NTOQ(rn,SGN(c[i]),r[i]);
    }
    for ( i = 0; i < n; i++ ) if ( r[i] ) break;
    if ( i < n ) {
        v.id = O_VECT; v.len = n; v.body = (pointer *)r;
        igcdv(&v,&d1);
        gcdn(NM(d0),NM(d1),&gn); NTOQ(gn,1,gcd);
        divsn(NM(d0),gn,&qn); NTOQ(qn,1,a);
        for ( i = 0; i < n; i++ ) {
            mulq(a,q[i],&u);
            if ( r[i] ) {
                divsn(NM(r[i]),gn,&qn); NTOQ(qn,SGN(r[i]),u1);
                addq(u,u1,&q[i]);
            } else
                q[i] = u;
        }
    }
    for ( i = 0; i < n; i++ ) c[i] = q[i];
}

void nd_mul_c(int mod,ND p,int mul)
{
    NM m;
    int c,c1;

    if ( !p ) return;
    if ( mul == 1 ) return;
    if ( mod == -1 )
        for ( m = BDY(p); m; m = NEXT(m) )
            CM(m) = _mulsf(CM(m),mul);
    else
        for ( m = BDY(p); m; m = NEXT(m) ) {
            c1 = CM(m); DMAR(c1,mul,0,mod,c); CM(m) = c;
        }
}

void nd_mul_c_q(ND p,P mul)
{
    NM m;
    P c;

    if ( !p ) return;
    if ( UNIQ(mul) ) return;
    for ( m = BDY(p); m; m = NEXT(m) ) {
        mulp(nd_vc,CP(m),mul,&c); CP(m) = c;
    }
}

void nd_mul_c_p(VL vl,ND p,P mul)
{
    NM m;
    P c;

    if ( !p ) return;
    for ( m = BDY(p); m; m = NEXT(m) ) {
        mulp(vl,CP(m),mul,&c); CP(m) = c;
    }
}

void nd_free(ND p)
{
    NM t,s;

    if ( !p ) return;
    t = BDY(p);
    while ( t ) {
        s = NEXT(t);
        FREENM(t);
        t = s;
    }
    FREEND(p);
}

void ndv_free(NDV p)
{
    GC_free(BDY(p));
}

void nd_append_red(UINT *d,int i)
{
    RHist m,m0;
    int h;

    NEWRHist(m);
    h = ndl_hash_value(d);
    m->index = i;
    ndl_copy(d,DL(m));
    NEXT(m) = nd_red[h];
    nd_red[h] = m;
}

UINT *ndv_compute_bound(NDV p)
{
    UINT *d1,*d2,*t;
    UINT u;
    int i,j,k,l,len,ind;
    NMV m;

    if ( !p )
        return 0;
    d1 = (UINT *)ALLOCA(nd_wpd*sizeof(UINT));
    d2 = (UINT *)ALLOCA(nd_wpd*sizeof(UINT));
    len = LEN(p);
    m = BDY(p); ndl_copy(DL(m),d1); NMV_ADV(m);
    for ( i = 1; i < len; i++, NMV_ADV(m) ) {
        ndl_max(DL(m),d1,d2);
        t = d1; d1 = d2; d2 = t;
    }
    l = nd_nvar+31;
    t = (UINT *)MALLOC_ATOMIC(l*sizeof(UINT));
    for ( i = nd_exporigin, ind = 0; i < nd_wpd; i++ ) {
        u = d1[i];
        k = (nd_epw-1)*nd_bpe;
        for ( j = 0; j < nd_epw; j++, k -= nd_bpe, ind++ )
            t[ind] = (u>>k)&nd_mask0;
    }
    for ( ; ind < l; ind++ ) t[ind] = 0;
    return t;
}

UINT *nd_compute_bound(ND p)
{
    UINT *d1,*d2,*t;
    UINT u;
    int i,j,k,l,len,ind;
    NM m;

    if ( !p )
        return 0;
    d1 = (UINT *)ALLOCA(nd_wpd*sizeof(UINT));
    d2 = (UINT *)ALLOCA(nd_wpd*sizeof(UINT));
    len = LEN(p);
    m = BDY(p); ndl_copy(DL(m),d1); m = NEXT(m);
    for ( m = NEXT(m); m; m = NEXT(m) ) {
        ndl_lcm(DL(m),d1,d2);
        t = d1; d1 = d2; d2 = t;
    }
    l = nd_nvar+31;
    t = (UINT *)MALLOC_ATOMIC(l*sizeof(UINT));
    for ( i = nd_exporigin, ind = 0; i < nd_wpd; i++ ) {
        u = d1[i];
        k = (nd_epw-1)*nd_bpe;
        for ( j = 0; j < nd_epw; j++, k -= nd_bpe, ind++ )
            t[ind] = (u>>k)&nd_mask0;
    }
    for ( ; ind < l; ind++ ) t[ind] = 0;
    return t;
}

/* if nd_module == 1 then d[nd_exporigin-1] indicates the position */
/* of a term. In this case we need additional 1 word. */

int nd_get_exporigin(struct order_spec *ord)
{
    switch ( ord->id ) {
        case 0: case 2: case 256: case 258:
            return 1+nd_module;
        case 1: case 257:
            /* block order */
            /* poly ring d[0]:weight d[1]:w0,...,d[nd_exporigin-1]:w(n-1) */
            /* module d[0]:weight d[1]:w0,...,d[nd_exporigin-2]:w(n-1) */
            return ord->ord.block.length+1+nd_module;
        case 3: case 259:
            error("nd_get_exporigin : composite order is not supported yet.");
    }
}

void nd_setup_parameters(int nvar,int max) {
    int i,j,n,elen,ord_o,ord_l,l,s,wpd;
    struct order_pair *op;

    nd_nvar = nvar;
    if ( max ) {
        /* XXX */
        if ( do_weyl ) nd_bpe = 32;
        else if ( max < 2 ) nd_bpe = 1;
        else if ( max < 4 ) nd_bpe = 2;
        else if ( max < 8 ) nd_bpe = 3;
        else if ( max < 16 ) nd_bpe = 4;
        else if ( max < 32 ) nd_bpe = 5;
        else if ( max < 64 ) nd_bpe = 6;
        else if ( max < 256 ) nd_bpe = 8;
        else if ( max < 1024 ) nd_bpe = 10;
        else if ( max < 65536 ) nd_bpe = 16;
        else nd_bpe = 32;
    }
    nd_epw = (sizeof(UINT)*8)/nd_bpe;
    elen = nd_nvar/nd_epw+(nd_nvar%nd_epw?1:0);
    nd_exporigin = nd_get_exporigin(nd_ord);
    wpd = nd_exporigin+elen;
    if ( nd_module )
        nd_mpos = nd_exporigin-1;
    else
        nd_mpos = -1;
    if ( wpd != nd_wpd ) {
        nd_free_private_storage();
        nd_wpd = wpd;
    }
    if ( nd_bpe < 32 ) {
        nd_mask0 = (1<<nd_bpe)-1;
    } else {
        nd_mask0 = 0xffffffff;
    }
    bzero(nd_mask,sizeof(nd_mask));
    nd_mask1 = 0;
    for ( i = 0; i < nd_epw; i++ ) {
        nd_mask[nd_epw-i-1] = (nd_mask0<<(i*nd_bpe));
        nd_mask1 |= (1<<(nd_bpe-1))<<(i*nd_bpe);
    }
    nmv_adv = ROUND_FOR_ALIGN(sizeof(struct oNMV)+(nd_wpd-1)*sizeof(UINT));
    nd_epos = nd_create_epos(nd_ord);
    nd_blockmask = nd_create_blockmask(nd_ord);
    nd_work_vector = (int *)REALLOC(nd_work_vector,nd_nvar*sizeof(int));
}

ND_pairs nd_reconstruct(int trace,ND_pairs d)
{
    int i,obpe,oadv,h;
    static NM prev_nm_free_list;
    static ND_pairs prev_ndp_free_list;
    RHist mr0,mr;
    RHist r;
    RHist *old_red;
    ND_pairs s0,s,t;
    EPOS oepos;

    obpe = nd_bpe;
    oadv = nmv_adv;
    oepos = nd_epos;
    if ( obpe < 2 ) nd_bpe = 2;
    else if ( obpe < 3 ) nd_bpe = 3;
    else if ( obpe < 4 ) nd_bpe = 4;
    else if ( obpe < 5 ) nd_bpe = 5;
    else if ( obpe < 6 ) nd_bpe = 6;
    else if ( obpe < 8 ) nd_bpe = 8;
    else if ( obpe < 10 ) nd_bpe = 10;
    else if ( obpe < 16 ) nd_bpe = 16;
    else if ( obpe < 32 ) nd_bpe = 32;
    else error("nd_reconstruct : exponent too large");

    nd_setup_parameters(nd_nvar,0);
    prev_nm_free_list = _nm_free_list;
    prev_ndp_free_list = _ndp_free_list;
    _nm_free_list = 0;
    _ndp_free_list = 0;
    for ( i = nd_psn-1; i >= 0; i-- ) ndv_realloc(nd_ps[i],obpe,oadv,oepos);
    if ( trace )
        for ( i = nd_psn-1; i >= 0; i-- )
            ndv_realloc(nd_ps_trace[i],obpe,oadv,oepos);
    s0 = 0;
    for ( t = d; t; t = NEXT(t) ) {
        NEXTND_pairs(s0,s);
        s->i1 = t->i1;
        s->i2 = t->i2;
        SG(s) = SG(t);
        ndl_reconstruct(LCM(t),LCM(s),obpe,oepos);
    }
    
    old_red = (RHist *)ALLOCA(REDTAB_LEN*sizeof(RHist));
    for ( i = 0; i < REDTAB_LEN; i++ ) {
        old_red[i] = nd_red[i];
        nd_red[i] = 0;
    }
    for ( i = 0; i < REDTAB_LEN; i++ )
        for ( r = old_red[i]; r; r = NEXT(r) ) {
            NEWRHist(mr);
            mr->index = r->index;
            SG(mr) = SG(r);
            ndl_reconstruct(DL(r),DL(mr),obpe,oepos);
            h = ndl_hash_value(DL(mr));
            NEXT(mr) = nd_red[h];
            nd_red[h] = mr;
        }
    for ( i = 0; i < REDTAB_LEN; i++ ) old_red[i] = 0;
    old_red = 0;
    for ( i = 0; i < nd_psn; i++ ) {
        NEWRHist(r); SG(r) = SG(nd_psh[i]);
        ndl_reconstruct(DL(nd_psh[i]),DL(r),obpe,oepos);
        nd_psh[i] = r;
    }
    if ( s0 ) NEXT(s) = 0;
    prev_nm_free_list = 0;
    prev_ndp_free_list = 0;
#if 0
    GC_gcollect();
#endif
    return s0;
}

void ndl_reconstruct(UINT *d,UINT *r,int obpe,EPOS oepos)
{
    int n,i,ei,oepw,omask0,j,s,ord_l,l;
    struct order_pair *op;

    n = nd_nvar;
    oepw = (sizeof(UINT)*8)/obpe;
    omask0 = (1<<obpe)-1;
    TD(r) = TD(d);
    for ( i = nd_exporigin; i < nd_wpd; i++ ) r[i] = 0;
    if ( nd_blockmask ) {
        l = nd_blockmask->n;
        op = nd_blockmask->order_pair;
        for ( i = 1; i < nd_exporigin; i++ )
            r[i] = d[i];
        for ( j = 0, s = 0; j < l; j++ ) {
            ord_l = op[j].length;
            for ( i = 0; i < ord_l; i++, s++ ) {
                ei =  GET_EXP_OLD(d,s);
                PUT_EXP(r,s,ei);
            }
        }
    } else {
        for ( i = 0; i < n; i++ ) {
            ei = GET_EXP_OLD(d,i);
            PUT_EXP(r,i,ei);
        }
    }
    if ( nd_module ) MPOS(r) = MPOS(d);
}

ND nd_copy(ND p)
{
    NM m,mr,mr0;
    int c,n;
    ND r;

    if ( !p )
        return 0;
    else {
        for ( mr0 = 0, m = BDY(p); m; m = NEXT(m) ) {
            NEXTNM(mr0,mr);
            CM(mr) = CM(m);
            ndl_copy(DL(m),DL(mr));
        }
        NEXT(mr) = 0; 
        MKND(NV(p),mr0,LEN(p),r);
        SG(r) = SG(p);
        return r;
    }
}

int nd_sp(int mod,int trace,ND_pairs p,ND *rp)
{
    NM m1,m2;
    NDV p1,p2;
    ND t1,t2;
    UINT *lcm;
    P gp,tp;
    Q g,t,iq;
    int td;
    LIST hist;
    NODE node;
    DP d;

    if ( !mod && nd_demand ) {
        p1 = ndv_load(p->i1); p2 = ndv_load(p->i2);
    } else {
        if ( trace ) {
            p1 = nd_ps_trace[p->i1]; p2 = nd_ps_trace[p->i2];
        } else {
            p1 = nd_ps[p->i1]; p2 = nd_ps[p->i2];
        }
    }
    lcm = LCM(p);
    NEWNM(m1); ndl_sub(lcm,HDL(p1),DL(m1));
    if ( ndl_check_bound2(p->i1,DL(m1)) ) {
        FREENM(m1); return 0;
    }
    NEWNM(m2); ndl_sub(lcm,HDL(p2),DL(m2));
    if ( ndl_check_bound2(p->i2,DL(m2)) ) {
        FREENM(m1); FREENM(m2); return 0;
    }

    if ( mod == -1 ) {
        CM(m1) = HCM(p2); CM(m2) = _chsgnsf(HCM(p1));
    } else if ( mod ) {
        CM(m1) = HCM(p2); CM(m2) = mod-HCM(p1); 
    } else if ( nd_vc ) {
        ezgcdpz(nd_vc,HCP(p1),HCP(p2),&gp);
        divsp(nd_vc,HCP(p2),gp,&CP(m1));
        divsp(nd_vc,HCP(p1),gp,&tp); chsgnp(tp,&CP(m2));
    } else {
        igcd_cofactor(HCQ(p1),HCQ(p2),&g,&t,&CQ(m1)); chsgnq(t,&CQ(m2));
    }
    t1 = ndv_mul_nm(mod,m1,p1); t2 = ndv_mul_nm(mod,m2,p2);
    *rp = nd_add(mod,t1,t2);
    if ( GenTrace ) {
        /* nd_tracelist is initialized */
        STOQ(p->i1,iq); nmtodp(mod,m1,&d); node = mknode(4,ONE,iq,d,ONE);
        MKLIST(hist,node); MKNODE(nd_tracelist,hist,0);
        STOQ(p->i2,iq); nmtodp(mod,m2,&d); node = mknode(4,ONE,iq,d,ONE);
        MKLIST(hist,node); MKNODE(node,hist,nd_tracelist);
        nd_tracelist = node;
    }
    FREENM(m1); FREENM(m2);
    return 1;
}

void ndv_mul_c(int mod,NDV p,int mul)
{
    NMV m;
    int c,c1,len,i;

    if ( !p ) return;
    len = LEN(p);
    if ( mod == -1 )
        for ( m = BDY(p), i = 0; i < len; i++, NMV_ADV(m) ) 
            CM(m) = _mulsf(CM(m),mul);
    else
        for ( m = BDY(p), i = 0; i < len; i++, NMV_ADV(m) ) {
            c1 = CM(m); DMAR(c1,mul,0,mod,c); CM(m) = c;
        }
}

void ndv_mul_c_q(NDV p,Q mul)
{
    NMV m;
    Q c;
    int len,i;

    if ( !p ) return;
    len = LEN(p);
    for ( m = BDY(p), i = 0; i < len; i++, NMV_ADV(m) ) {
        mulq(CQ(m),mul,&c); CQ(m) = c;
    }
}

ND weyl_ndv_mul_nm(int mod,NM m0,NDV p) {
    int n2,i,j,l,n,tlen;
    UINT *d0;
    NM *tab,*psum;
    ND s,r;
    NM t;
    NMV m1;

    if ( !p ) return 0;
    n = NV(p); n2 = n>>1;
    d0 = DL(m0);
    l = LEN(p);
    for ( i = 0, tlen = 1; i < n2; i++ ) tlen *= (GET_EXP(d0,n2+i)+1);
    tab = (NM *)ALLOCA(tlen*sizeof(NM));
    psum = (NM *)ALLOCA(tlen*sizeof(NM));
    for ( i = 0; i < tlen; i++ ) psum[i] = 0;
    m1 = (NMV)(((char *)BDY(p))+nmv_adv*(l-1));
    for ( i = l-1; i >= 0; i--, NMV_PREV(m1) ) {
        /* m0(NM) * m1(NMV) => tab(NM) */
        weyl_mul_nm_nmv(n,mod,m0,m1,tab,tlen);
        for ( j = 0; j < tlen; j++ ) {
            if ( tab[j] ) {
                NEXT(tab[j]) = psum[j];    psum[j] = tab[j];
            }
        }        
    }
    for ( i = tlen-1, r = 0; i >= 0; i-- )
        if ( psum[i] ) {
            for ( j = 0, t = psum[i]; t; t = NEXT(t), j++ );
            MKND(n,psum[i],j,s);
            r = nd_add(mod,r,s);
        }
    if ( r ) SG(r) = SG(p)+TD(d0);
    return r;
}

/* product of monomials */
/* XXX block order is not handled correctly */

void weyl_mul_nm_nmv(int n,int mod,NM m0,NMV m1,NM *tab,int tlen)
{
    int i,n2,j,s,curlen,homo,h,a,b,k,l,u,min;
    UINT *d0,*d1,*d,*dt,*ctab;
    Q *ctab_q;
    Q q,q1;
    UINT c0,c1,c;
    NM *p;
    NM m,t;
    int mpos;

    for ( i = 0; i < tlen; i++ ) tab[i] = 0;
    if ( !m0 || !m1 ) return;
    d0 = DL(m0); d1 = DL(m1); n2 = n>>1;
    if ( nd_module )
        if ( MPOS(d0) ) error("weyl_mul_nm_nmv : invalid operation");

    NEWNM(m); d = DL(m);
    if ( mod ) {
        c0 = CM(m0); c1 = CM(m1); DMAR(c0,c1,0,mod,c); CM(m) = c;
    } else
        mulq(CQ(m0),CQ(m1),&CQ(m));
    for ( i = 0; i < nd_wpd; i++ ) d[i] = 0;
    homo = n&1 ? 1 : 0;
    if ( homo ) {
        /* offset of h-degree */
        h = GET_EXP(d0,n-1)+GET_EXP(d1,n-1);
        PUT_EXP(DL(m),n-1,h);
        TD(DL(m)) = h;
        if ( nd_blockmask ) ndl_weight_mask(DL(m));
    }
    tab[0] = m;
    NEWNM(m); d = DL(m);
    for ( i = 0, curlen = 1; i < n2; i++ ) {
        a = GET_EXP(d0,i); b = GET_EXP(d1,n2+i);
        k = GET_EXP(d0,n2+i); l = GET_EXP(d1,i);
        /* xi^a*(Di^k*xi^l)*Di^b */
        a += l; b += k;
        s = MUL_WEIGHT(a,i)+MUL_WEIGHT(b,n2+i);
        if ( !k || !l ) {
            for ( j = 0; j < curlen; j++ )
                if ( t = tab[j] ) {
                    dt = DL(t);
                    PUT_EXP(dt,i,a); PUT_EXP(dt,n2+i,b); TD(dt) += s;
                    if ( nd_blockmask ) ndl_weight_mask(dt);
                }
            curlen *= k+1;
            continue;
        }
        min = MIN(k,l);
        if ( mod ) {
            ctab = (UINT *)ALLOCA((min+1)*sizeof(UINT));
            mkwcm(k,l,mod,ctab);
        } else {
            ctab_q = (Q *)ALLOCA((min+1)*sizeof(Q));
            mkwc(k,l,ctab_q);
        }
        for ( j = min; j >= 0; j-- ) {
            for ( u = 0; u < nd_wpd; u++ ) d[u] = 0;
            PUT_EXP(d,i,a-j); PUT_EXP(d,n2+i,b-j);
            h = MUL_WEIGHT(a-j,i)+MUL_WEIGHT(b-j,n2+i);
            if ( homo ) {
                TD(d) = s;
                PUT_EXP(d,n-1,s-h);
            } else TD(d) = h;
            if ( nd_blockmask ) ndl_weight_mask(d);
            if ( mod ) c = ctab[j];
            else q = ctab_q[j];
            p = tab+curlen*j;
            if ( j == 0 ) {
                for ( u = 0; u < curlen; u++, p++ ) {
                    if ( tab[u] ) {
                        ndl_addto(DL(tab[u]),d);
                        if ( mod ) {
                            c0 = CM(tab[u]); DMAR(c0,c,0,mod,c1); CM(tab[u]) = c1;
                        } else {
                            mulq(CQ(tab[u]),q,&q1); CQ(tab[u]) = q1;
                        }
                    }
                }
            } else {
                for ( u = 0; u < curlen; u++, p++ ) {
                    if ( tab[u] ) {
                        NEWNM(t);
                        ndl_add(DL(tab[u]),d,DL(t));
                        if ( mod ) {
                            c0 = CM(tab[u]); DMAR(c0,c,0,mod,c1); CM(t) = c1;
                        } else
                            mulq(CQ(tab[u]),q,&CQ(t));
                        *p = t;
                    }
                }
            }
        }
        curlen *= k+1;
    }
    FREENM(m);
    if ( nd_module ) {
        mpos = MPOS(d1);
        for ( i = 0; i < tlen; i++ )
            if ( tab[i] ) {
                d = DL(tab[i]);
                MPOS(d) = mpos;
                TD(d) = ndl_weight(d);
            }
    }
}

ND ndv_mul_nm_symbolic(NM m0,NDV p)
{
    NM mr,mr0;
    NMV m;
    UINT *d,*dt,*dm;
    int c,n,td,i,c1,c2,len;
    Q q;
    ND r;

    if ( !p ) return 0;
    else {
        n = NV(p); m = BDY(p);
        d = DL(m0);
        len = LEN(p);
        mr0 = 0;
        td = TD(d);
        c = CM(m0);
        for ( i = 0; i < len; i++, NMV_ADV(m) ) {
            NEXTNM(mr0,mr);
            CM(mr) = 1;
            ndl_add(DL(m),d,DL(mr));
        }
        NEXT(mr) = 0; 
        MKND(NV(p),mr0,len,r);
        SG(r) = SG(p) + TD(d);
        return r;
    }
}

ND ndv_mul_nm(int mod,NM m0,NDV p)
{
    NM mr,mr0;
    NMV m;
    UINT *d,*dt,*dm;
    int c,n,td,i,c1,c2,len;
    P q;
    ND r;

    if ( !p ) return 0;
    else if ( do_weyl )
        if ( mod == -1 )
            error("ndv_mul_nm : not implemented (weyl)");
        else
            return weyl_ndv_mul_nm(mod,m0,p);
    else {
        n = NV(p); m = BDY(p);
        d = DL(m0);
        len = LEN(p);
        mr0 = 0;
        td = TD(d);
        if ( mod == -1 ) {
            c = CM(m0);
            for ( i = 0; i < len; i++, NMV_ADV(m) ) {
                NEXTNM(mr0,mr);
                CM(mr) = _mulsf(CM(m),c);
                ndl_add(DL(m),d,DL(mr));
            }
        } else if ( mod ) {
            c = CM(m0);
            for ( i = 0; i < len; i++, NMV_ADV(m) ) {
                NEXTNM(mr0,mr);
                c1 = CM(m);
                DMAR(c1,c,0,mod,c2);
                CM(mr) = c2;
                ndl_add(DL(m),d,DL(mr));
            }
        } else {
            q = CP(m0);
            for ( i = 0; i < len; i++, NMV_ADV(m) ) {
                NEXTNM(mr0,mr);
                mulp(nd_vc,CP(m),q,&CP(mr));
                ndl_add(DL(m),d,DL(mr));
            }
        }
        NEXT(mr) = 0; 
        MKND(NV(p),mr0,len,r);
        SG(r) = SG(p) + TD(d);
        return r;
    }
}

ND nd_quo(int mod,PGeoBucket bucket,NDV d)
{
    NM mq0,mq;
    NMV tm;
    Q q;
    int i,nv,sg,c,c1,c2,hindex;
    ND p,t,r;
    N tnm;

    if ( bucket->m < 0 ) return 0;
    else {
        nv = NV(d);
        mq0 = 0;
        tm = (NMV)ALLOCA(nmv_adv);
        while ( 1 ) {
            hindex = mod?head_pbucket(mod,bucket):head_pbucket_q(bucket);
            if ( hindex < 0 ) break;
            p = bucket->body[hindex];
            NEXTNM(mq0,mq);
            ndl_sub(HDL(p),HDL(d),DL(mq));
            ndl_copy(DL(mq),DL(tm));
            if ( mod ) {
                c1 = invm(HCM(d),mod); c2 = HCM(p);
                DMAR(c1,c2,0,mod,c); CM(mq) = c;
                CM(tm) = mod-c;
            } else {
                divsn(NM(HCQ(p)),NM(HCQ(d)),&tnm);
                NTOQ(tnm,SGN(HCQ(p))*SGN(HCQ(d)),CQ(mq));
                chsgnq(CQ(mq),&CQ(tm));
            }
            t = ndv_mul_nmv_trunc(mod,tm,d,HDL(d));
            bucket->body[hindex] = nd_remove_head(p);
            t = nd_remove_head(t);
            add_pbucket(mod,bucket,t);
        }
        if ( !mq0 )
            r = 0;
        else {
            NEXT(mq) = 0;
            for ( i = 0, mq = mq0; mq; mq = NEXT(mq), i++ );
            MKND(nv,mq0,i,r);
            /* XXX */
            SG(r) = HTD(r);
        }
        return r;
    }
}

void ndv_realloc(NDV p,int obpe,int oadv,EPOS oepos)
{
    NMV m,mr,mr0,t;
    int len,i,k;

    if ( !p ) return;
    m = BDY(p); len = LEN(p);
    mr0 = nmv_adv>oadv?(NMV)REALLOC(BDY(p),len*nmv_adv):BDY(p);
    m = (NMV)((char *)mr0+(len-1)*oadv);
    mr = (NMV)((char *)mr0+(len-1)*nmv_adv);
    t = (NMV)ALLOCA(nmv_adv);
    for ( i = 0; i < len; i++, NMV_OPREV(m), NMV_PREV(mr) ) {
        CQ(t) = CQ(m);
        for ( k = 0; k < nd_wpd; k++ ) DL(t)[k] = 0;
        ndl_reconstruct(DL(m),DL(t),obpe,oepos);
        CQ(mr) = CQ(t);
        ndl_copy(DL(t),DL(mr));
    }
    BDY(p) = mr0;
}

NDV ndv_dup_realloc(NDV p,int obpe,int oadv,EPOS oepos)
{
    NMV m,mr,mr0;
    int len,i;
    NDV r;

    if ( !p ) return 0;
    m = BDY(p); len = LEN(p);
    mr0 = mr = (NMV)MALLOC(len*nmv_adv);
    for ( i = 0; i < len; i++, NMV_OADV(m), NMV_ADV(mr) ) {
        ndl_zero(DL(mr));
        ndl_reconstruct(DL(m),DL(mr),obpe,oepos);
        CQ(mr) = CQ(m);
    }
    MKNDV(NV(p),mr0,len,r);
    SG(r) = SG(p);
    return r;
}

/* duplicate p */

NDV ndv_dup(int mod,NDV p)
{
    NDV d;
    NMV t,m,m0;
    int i,len;

    if ( !p ) return 0;
    len = LEN(p);
    m0 = m = (NMV)(mod?MALLOC_ATOMIC(len*nmv_adv):MALLOC(len*nmv_adv));
    for ( t = BDY(p), i = 0; i < len; i++, NMV_ADV(t), NMV_ADV(m) ) {
        ndl_copy(DL(t),DL(m));
        CQ(m) = CQ(t);
    }
    MKNDV(NV(p),m0,len,d);
    SG(d) = SG(p);
    return d;
}

ND nd_dup(ND p)
{
    ND d;
    NM t,m,m0;

    if ( !p ) return 0;
    for ( m0 = 0, t = BDY(p); t; t = NEXT(t) ) {
        NEXTNM(m0,m);
        ndl_copy(DL(t),DL(m));
        CQ(m) = CQ(t);
    }
    if ( m0 ) NEXT(m) = 0;
    MKND(NV(p),m0,LEN(p),d);
    SG(d) = SG(p);
    return d;
}

/* XXX if p->len == 0 then it represents 0 */

void ndv_mod(int mod,NDV p)
{
    NMV t,d;
    int r,s,u;
    int i,len,dlen;
    P cp;
    Q c;
    Obj gfs;

    if ( !p ) return;
    len = LEN(p);
    dlen = 0;
    if ( mod == -1 )
        for ( t = d = BDY(p), i = 0; i < len; i++, NMV_ADV(t) ) {
            simp_ff((Obj)CP(t),&gfs);
            r = FTOIF(CONT((GFS)gfs));
            CM(d) = r;
            ndl_copy(DL(t),DL(d));
            NMV_ADV(d);
            dlen++;    
        }
    else
        for ( t = d = BDY(p), i = 0; i < len; i++, NMV_ADV(t) ) {
            if ( nd_vc ) {
                nd_subst_vector(nd_vc,CP(t),nd_subst,&cp);
                c = (Q)cp;
            } else
                c = CQ(t);
            r = rem(NM(c),mod);
            if ( r ) {
                if ( SGN(c) < 0 )
                    r = mod-r;
                if ( DN(c) ) {
                    s = rem(DN(c),mod);
                    if ( !s )
                        error("ndv_mod : division by 0");
                    s = invm(s,mod);
                    DMAR(r,s,0,mod,u); r = u;
                }
                CM(d) = r;
                ndl_copy(DL(t),DL(d));
                NMV_ADV(d);
                dlen++;    
            }
        }
    LEN(p) = dlen;
}

NDV ptondv(VL vl,VL dvl,P p)
{
    ND nd;

    nd = ptond(vl,dvl,p);
    return ndtondv(0,nd);
}

void pltozpl(LIST l,Q *cont,LIST *pp)
{
    NODE nd,nd1;
    int n;
    P *pl;
    Q *cl;
    int i;
    P dmy;
    Q dvr;
    LIST r;

    nd = BDY(l); n = length(nd);
    pl = (P *)ALLOCA(n*sizeof(P));
    cl = (Q *)ALLOCA(n*sizeof(P));
    for ( i = 0; i < n; i++, nd = NEXT(nd) )
        ptozp((P)BDY(nd),1,&cl[i],&dmy);
    qltozl(cl,n,&dvr);
    nd = BDY(l);
    for ( i = 0; i < n; i++, nd = NEXT(nd) ) {
        divsp(CO,(P)BDY(nd),(P)dvr,&pl[i]);
    }
    nd = 0;
    for ( i = n-1; i >= 0; i-- ) {
        MKNODE(nd1,pl[i],nd); nd = nd1;
    }
    MKLIST(r,nd);
    *pp = r;
}

/* (a1,a2,...,an) -> a1*e(1)+...+an*e(n) */

NDV pltondv(VL vl,VL dvl,LIST p)
{
    int i;
    NODE t;
    ND r,ri;
    NM m;

    if ( !nd_module ) error("pltond : module order must be set");
    r = 0;
    for ( i = 1, t = BDY(p); t; t = NEXT(t), i++ ) {
        ri = ptond(vl,dvl,(P)BDY(t));
        if ( ri ) 
            for ( m = BDY(ri); m; m = NEXT(m) ) {
                MPOS(DL(m)) = i;
                TD(DL(m)) = ndl_weight(DL(m));
                if ( nd_blockmask ) ndl_weight_mask(DL(m));
            }
        r = nd_add(0,r,ri);
    }
    return ndtondv(0,r);
}

ND ptond(VL vl,VL dvl,P p)
{
    int n,i,j,k,e;
    VL tvl;
    V v;
    DCP dc;
    DCP *w;
    ND r,s,t,u;
    P x;
    int c;
    UINT *d;
    NM m,m0;

    if ( !p )
        return 0;
    else if ( NUM(p) ) {
        NEWNM(m);
        ndl_zero(DL(m));
        CQ(m) = (Q)p;
        NEXT(m) = 0;
        MKND(nd_nvar,m,1,r);
        SG(r) = 0;
        return r;
    } else {
        for ( dc = DC(p), k = 0; dc; dc = NEXT(dc), k++ );
        w = (DCP *)ALLOCA(k*sizeof(DCP));
        for ( dc = DC(p), j = 0; j < k; dc = NEXT(dc), j++ ) w[j] = dc;
        for ( i = 0, tvl = dvl, v = VR(p);
            tvl && tvl->v != v; tvl = NEXT(tvl), i++ );
        if ( !tvl ) {
            for ( j = k-1, s = 0, MKV(v,x); j >= 0; j-- ) {
                t = ptond(vl,dvl,COEF(w[j]));
                pwrp(vl,x,DEG(w[j]),&p);
                nd_mul_c_p(CO,t,p); s = nd_add(0,s,t);
            }
            return s;
        } else {
            NEWNM(m0); d = DL(m0);
            for ( j = k-1, s = 0; j >= 0; j-- ) {
                ndl_zero(d); e = QTOS(DEG(w[j])); PUT_EXP(d,i,e);
                TD(d) = MUL_WEIGHT(e,i);
                if ( nd_blockmask) ndl_weight_mask(d);
                if ( nd_module ) MPOS(d) = 0;
                t = ptond(vl,dvl,COEF(w[j]));
                for ( m = BDY(t); m; m = NEXT(m) )
                    ndl_addto(DL(m),d);
                SG(t) += TD(d);
                s = nd_add(0,s,t);
            }
            FREENM(m0);
            return s;
        }
    }
}

P ndvtop(int mod,VL vl,VL dvl,NDV p)
{
    VL tvl;
    int len,n,j,i,e;
    NMV m;
    Q q;
    P c;
    UINT *d;
    P s,r,u,t,w;
    GFS gfs;

    if ( !p ) return 0;
    else {
        len = LEN(p);
        n = NV(p);
        m = (NMV)(((char *)BDY(p))+nmv_adv*(len-1));
        for ( j = len-1, s = 0; j >= 0; j--, NMV_PREV(m) ) {
            if ( mod == -1 ) {
                e = IFTOF(CM(m)); MKGFS(e,gfs); c = (P)gfs;
            } else if ( mod ) {
                STOQ(CM(m),q); c = (P)q;
            } else
                c = CP(m);
            d = DL(m);
            for ( i = 0, t = c, tvl = dvl; i < n; tvl = NEXT(tvl), i++ ) {
                MKV(tvl->v,r); e = GET_EXP(d,i); STOQ(e,q);
                pwrp(vl,r,q,&u); mulp(vl,t,u,&w); t = w;
            }
            addp(vl,s,t,&u); s = u;
        }
        return s;
    }
}

LIST ndvtopl(int mod,VL vl,VL dvl,NDV p,int rank)
{
    VL tvl;
    int len,n,j,i,e;
    NMV m;
    Q q;
    P c;
    UINT *d;
    P s,r,u,t,w;
    GFS gfs;
    P *a;
    LIST l;
    NODE nd,nd1;

    if ( !p ) return 0;
    else {
        a = (P *)ALLOCA((rank+1)*sizeof(P));
        for ( i = 0; i <= rank; i++ ) a[i] = 0;
        len = LEN(p);
        n = NV(p);
        m = (NMV)(((char *)BDY(p))+nmv_adv*(len-1));
        for ( j = len-1; j >= 0; j--, NMV_PREV(m) ) {
            if ( mod == -1 ) {
                e = IFTOF(CM(m)); MKGFS(e,gfs); c = (P)gfs;
            } else if ( mod ) {
                STOQ(CM(m),q); c = (P)q;
            } else
                c = CP(m);
            d = DL(m);
            for ( i = 0, t = c, tvl = dvl; i < n; tvl = NEXT(tvl), i++ ) {
                MKV(tvl->v,r); e = GET_EXP(d,i); STOQ(e,q);
                pwrp(vl,r,q,&u); mulp(vl,t,u,&w); t = w;
            }
            addp(vl,a[MPOS(d)],t,&u); a[MPOS(d)] = u;
        }
        nd = 0;
        for ( i = rank; i > 0; i-- ) {
            MKNODE(nd1,a[i],nd); nd = nd1;
        }
        MKLIST(l,nd);
        return l;
    }
}

NDV ndtondv(int mod,ND p)
{
    NDV d;
    NMV m,m0;
    NM t;
    int i,len;

    if ( !p ) return 0;
    len = LEN(p);
    if ( mod )
        m0 = m = (NMV)GC_malloc_atomic_ignore_off_page(len*nmv_adv);
    else
        m0 = m = MALLOC(len*nmv_adv);
#if 0
    ndv_alloc += nmv_adv*len;
#endif
    for ( t = BDY(p), i = 0; t; t = NEXT(t), i++, NMV_ADV(m) ) {
        ndl_copy(DL(t),DL(m));
        CQ(m) = CQ(t);
    }
    MKNDV(NV(p),m0,len,d);
    SG(d) = SG(p);
    return d;
}

ND ndvtond(int mod,NDV p)
{
    ND d;
    NM m,m0;
    NMV t;
    int i,len;

    if ( !p ) return 0;
    m0 = 0;
    len = p->len;
    for ( t = BDY(p), i = 0; i < len; NMV_ADV(t), i++ ) {
        NEXTNM(m0,m);
        ndl_copy(DL(t),DL(m));
        CQ(m) = CQ(t);
    }
    NEXT(m) = 0;
    MKND(NV(p),m0,len,d);
    SG(d) = SG(p);
    return d;
}

void ndv_print(NDV p)
{
    NMV m;
    int i,len;
    
    if ( !p ) printf("0\n");
    else {
        len = LEN(p);
        for ( m = BDY(p), i = 0; i < len; i++, NMV_ADV(m) ) {
            if ( CM(m) & 0x80000000 ) printf("+@_%d*",IFTOF(CM(m)));
            else printf("+%d*",CM(m));
            ndl_print(DL(m));
        }
        printf("\n");
    }
}

void ndv_print_q(NDV p)
{
    NMV m;
    int i,len;
    
    if ( !p ) printf("0\n");
    else {
        len = LEN(p);
        for ( m = BDY(p), i = 0; i < len; i++, NMV_ADV(m) ) {
            printf("+");
            printexpr(CO,(Obj)CQ(m));
            printf("*");
            ndl_print(DL(m));
        }
        printf("\n");
    }
}

NODE ndv_reducebase(NODE x,int *perm)
{
    int len,i,j;
    NDVI w;
    NODE t,t0;

    len = length(x);
    w = (NDVI)ALLOCA(len*sizeof(struct oNDVI));
    for ( i = 0, t = x; i < len; i++, t = NEXT(t) ) {
        w[i].p = BDY(t); w[i].i = perm[i];
    }
    for ( i = 0; i < len; i++ ) {
        for ( j = 0; j < i; j++ ) {
            if ( w[i].p && w[j].p )
                if ( ndl_reducible(HDL(w[i].p),HDL(w[j].p)) ) w[i].p = 0;
                else if ( ndl_reducible(HDL(w[j].p),HDL(w[i].p)) ) w[j].p = 0;
        }
    }
    for ( i = j = 0, t0 = 0; i < len; i++ ) {
        if ( w[i].p ) { 
            NEXTNODE(t0,t); BDY(t) = (pointer)w[i].p; 
            perm[j++] = w[i].i;
        }
    }
    NEXT(t) = 0; x = t0;
    return x;
}

/* XXX incomplete */

void nd_init_ord(struct order_spec *ord)
{
    nd_module = (ord->id >= 256);
    switch ( ord->id ) {
        case 0:
            switch ( ord->ord.simple ) {
                case 0:
                    nd_dcomp = 1;
                    nd_isrlex = 1;
                    break;
                case 1:
                    nd_dcomp = 1;
                    nd_isrlex = 0;
                    break;
                case 2:
                    nd_dcomp = 0;
                    nd_isrlex = 0;
                    ndl_compare_function = ndl_lex_compare;
                    break;
                case 11:
                    /* XXX */
                    nd_dcomp = 0;
                    nd_isrlex = 1;
                    ndl_compare_function = ndl_ww_lex_compare;
                    break;
                default:
                    error("nd_gr : unsupported order");
            }
            break;
        case 1:
            /* block order */
            /* XXX */
            nd_dcomp = -1;
            nd_isrlex = 0;
            ndl_compare_function = ndl_block_compare;
            break;
        case 2:
            /* matrix order */
            /* XXX */
            nd_dcomp = -1;
            nd_isrlex = 0;
            nd_matrix_len = ord->ord.matrix.row;
            nd_matrix = ord->ord.matrix.matrix;
            ndl_compare_function = ndl_matrix_compare;
            break;
        case 3:
            /* composite order */
            nd_dcomp = -1;
            nd_isrlex = 0;
            nd_worb_len = ord->ord.composite.length;
            nd_worb = ord->ord.composite.w_or_b;
            ndl_compare_function = ndl_composite_compare;
            break;

        /* module order */
        case 256:
            nd_ispot = ord->ispot;
            nd_dcomp = -1;
            switch ( ord->ord.simple ) {
                case 0:
                    nd_isrlex = 1;
                    ndl_compare_function = ndl_module_grlex_compare;
                    break;
                case 1:
                    nd_isrlex = 0;
                    ndl_compare_function = ndl_module_glex_compare;
                    break;
                case 2:
                    nd_isrlex = 0;
                    ndl_compare_function = ndl_module_lex_compare;
                    break;
                default:
                    error("nd_gr : unsupported order");
            }
            break;
        case 257:
            /* block order */
            ndl_compare_function = ndl_module_block_compare;
            break;
        case 258:
            /* matrix order */
            nd_matrix_len = ord->ord.matrix.row;
            nd_matrix = ord->ord.matrix.matrix;
            ndl_compare_function = ndl_module_matrix_compare;
            break;
        case 259:
            /* composite order */
            nd_worb_len = ord->ord.composite.length;
            nd_worb = ord->ord.composite.w_or_b;
            ndl_compare_function = ndl_module_composite_compare;
            break;
    }
    nd_ord = ord;
}

BlockMask nd_create_blockmask(struct order_spec *ord)
{
    int n,i,j,s,l;
    UINT *t;
    BlockMask bm;

    /* we only create mask table for block order */
    if ( ord->id != 1 && ord->id != 257 )
        return 0;
    n = ord->ord.block.length;
    bm = (BlockMask)MALLOC(sizeof(struct oBlockMask));
    bm->n = n;
    bm->order_pair = ord->ord.block.order_pair;
    bm->mask = (UINT **)MALLOC(n*sizeof(UINT *));
    for ( i = 0, s = 0; i < n; i++ ) {
        bm->mask[i] = t = (UINT *)MALLOC_ATOMIC(nd_wpd*sizeof(UINT));
        for ( j = 0; j < nd_wpd; j++ ) t[j] = 0;
        l = bm->order_pair[i].length;
        for ( j = 0; j < l; j++, s++ ) PUT_EXP(t,s,nd_mask0);        
    }
    return bm;
}

EPOS nd_create_epos(struct order_spec *ord)
{
    int i,j,l,s,ord_l,ord_o;
    EPOS epos;
    struct order_pair *op;

    epos = (EPOS)MALLOC_ATOMIC(nd_nvar*sizeof(struct oEPOS));
    switch ( ord->id ) {
        case 0: case 256:
            if ( nd_isrlex ) {
                for ( i = 0; i < nd_nvar; i++ ) {
                    epos[i].i = nd_exporigin + (nd_nvar-1-i)/nd_epw;
                    epos[i].s = (nd_epw-((nd_nvar-1-i)%nd_epw)-1)*nd_bpe;
                }
            } else {
                for ( i = 0; i < nd_nvar; i++ ) {
                    epos[i].i = nd_exporigin + i/nd_epw;
                    epos[i].s = (nd_epw-(i%nd_epw)-1)*nd_bpe;
                }
            }
            break;
        case 1: case 257:
            /* block order */
            l = ord->ord.block.length;
            op = ord->ord.block.order_pair;
            for ( j = 0, s = 0; j < l; j++ ) {
                ord_o = op[j].order;
                ord_l = op[j].length;
                if ( !ord_o )
                    for ( i = 0; i < ord_l; i++ ) {
                        epos[s+i].i = nd_exporigin + (s+ord_l-i-1)/nd_epw;
                        epos[s+i].s = (nd_epw-((s+ord_l-i-1)%nd_epw)-1)*nd_bpe;
                    }
                else
                    for ( i = 0; i < ord_l; i++ ) {
                        epos[s+i].i = nd_exporigin + (s+i)/nd_epw;
                        epos[s+i].s = (nd_epw-((s+i)%nd_epw)-1)*nd_bpe;
                    }
                s += ord_l;
            }
            break;
        case 2:
            /* matrix order */
        case 3:
            /* composite order */
        default:
            for ( i = 0; i < nd_nvar; i++ ) {
                epos[i].i = nd_exporigin + i/nd_epw;
                epos[i].s = (nd_epw-(i%nd_epw)-1)*nd_bpe;
            }
            break;
    }
    return epos;
}

/* external interface */

void nd_nf_p(P f,LIST g,LIST v,int m,struct order_spec *ord,P *rp)
{
    NODE t,in0,in;
    ND nd,nf;
    NDV ndv;
    VL vv,tv;
    int stat,nvar,max,e;
    union oNDC dn;
    Q cont;
    P pp;

    if ( !f ) {
        *rp = 0;
        return;
    }
    pltovl(v,&vv);
    for ( nvar = 0, tv = vv; tv; tv = NEXT(tv), nvar++ );

    /* get the degree bound */
    for ( t = BDY(g), max = 0; t; t = NEXT(t) )
        for ( tv = vv; tv; tv = NEXT(tv) ) {
            e = getdeg(tv->v,(P)BDY(t));
            max = MAX(e,max);
        }
    for ( tv = vv; tv; tv = NEXT(tv) ) {
        e = getdeg(tv->v,f);
        max = MAX(e,max);
    }

    nd_init_ord(ord);
    nd_setup_parameters(nvar,max);

    /* conversion to ndv */
    for ( in0 = 0, t = BDY(g); t; t = NEXT(t) ) {
        NEXTNODE(in0,in);
        ptozp((P)BDY(t),1,&cont,&pp);
        BDY(in) = (pointer)ptondv(CO,vv,pp);
        if ( m ) ndv_mod(m,(NDV)BDY(in));
    }
    NEXTNODE(in0,in);
    BDY(in) = (pointer)ptondv(CO,vv,f);
    if ( m ) ndv_mod(m,(NDV)BDY(in));
    NEXT(in) = 0;

    /* dont sort, dont removecont */
    ndv_setup(m,0,in0,1,1);
    nd_psn--;
    nd_scale=2;
    while ( 1 ) {
        nd = (pointer)ndvtond(m,nd_ps[nd_psn]);
        stat = nd_nf(m,0,nd,nd_ps,1,0,&nf);
        if ( !stat ) {
            nd_psn++;
            nd_reconstruct(0,0);
            nd_psn--;
        } else
            break;
    }
    *rp = ndvtop(m,CO,vv,ndtondv(m,nf));
}

int nd_to_vect(int mod,UINT *s0,int n,ND d,UINT *r)
{
    NM m;
    UINT *t,*s;
    int i;

    for ( i = 0; i < n; i++ ) r[i] = 0;
    for ( i = 0, s = s0, m = BDY(d); m; m = NEXT(m) ) {
        t = DL(m);
        for ( ; !ndl_equal(t,s); s += nd_wpd, i++ );
        r[i] = CM(m);
    }
    for ( i = 0; !r[i]; i++ );
    return i;
}

int nd_to_vect_q(UINT *s0,int n,ND d,Q *r)
{
    NM m;
    UINT *t,*s;
    int i;

    for ( i = 0; i < n; i++ ) r[i] = 0;
    for ( i = 0, s = s0, m = BDY(d); m; m = NEXT(m) ) {
        t = DL(m);
        for ( ; !ndl_equal(t,s); s += nd_wpd, i++ );
        r[i] = CQ(m);
    }
    for ( i = 0; !r[i]; i++ );
    return i;
}

Q *nm_ind_pair_to_vect(int mod,UINT *s0,int n,NM_ind_pair pair)
{
    NM m;
    NMV mr;
    UINT *d,*t,*s;
    NDV p;
    int i,j,len;
    Q *r;

    m = pair->mul;
    d = DL(m);
    p = nd_ps[pair->index];
    len = LEN(p);
    r = (Q *)CALLOC(n,sizeof(Q));
    t = (UINT *)ALLOCA(nd_wpd*sizeof(UINT));
    for ( i = j = 0, s = s0, mr = BDY(p); j < len; j++, NMV_ADV(mr) ) {
        ndl_add(d,DL(mr),t);    
        for ( ; !ndl_equal(t,s); s += nd_wpd, i++ );
        r[i] = CQ(mr);
    }
    return r;
}

IndArray nm_ind_pair_to_vect_compress(int mod,UINT *s0,int n,NM_ind_pair pair)
{
    NM m;
    NMV mr;
    UINT *d,*t,*s;
    NDV p;
    unsigned char *ivc;
    unsigned short *ivs;
    UINT *v,*ivi,*s0v;
    int i,j,len,prev,diff,cdiff;
    IndArray r;

    m = pair->mul;
    d = DL(m);
    p = nd_ps[pair->index];
    len = LEN(p);
    t = (UINT *)ALLOCA(nd_wpd*sizeof(UINT));
    v = (unsigned int *)ALLOCA(len*sizeof(unsigned int));
    for ( i = j = 0, s = s0, mr = BDY(p); j < len; j++, NMV_ADV(mr) ) {
        ndl_add(d,DL(mr),t);    
        for ( ; !ndl_equal(t,s); s += nd_wpd, i++ );
        v[j] = i;
    }
    r = (IndArray)MALLOC(sizeof(struct oIndArray));
    r->head = v[0];
    diff = 0;
    for ( i = 1; i < len; i++ ) {
        cdiff = v[i]-v[i-1]; diff = MAX(cdiff,diff);
    }
    if ( diff < 256 ) {
        r->width = 1;
        ivc = (unsigned char *)MALLOC_ATOMIC(len*sizeof(unsigned char));
        r->index.c = ivc;
        for ( i = 1, ivc[0] = 0; i < len; i++ ) ivc[i] = v[i]-v[i-1];
    } else if ( diff < 65536 ) {
        r->width = 2;
        ivs = (unsigned short *)MALLOC_ATOMIC(len*sizeof(unsigned short));
        r->index.s = ivs;
        for ( i = 1, ivs[0] = 0; i < len; i++ ) ivs[i] = v[i]-v[i-1];
    } else {
        r->width = 4;
        ivi = (unsigned int *)MALLOC_ATOMIC(len*sizeof(unsigned int));
        r->index.i = ivi;
        for ( i = 1, ivi[0] = 0; i < len; i++ ) ivi[i] = v[i]-v[i-1];
    }
    return r;
}

int compress_array(Q *svect,Q *cvect,int n)
{
    int i,j;

    for ( i = j = 0; i < n; i++ )
        if ( svect[i] ) cvect[j++] = svect[i];
    return j;
}

void expand_array(Q *svect,Q *cvect,int n)
{
    int i,j;

    for ( i = j = 0; j < n;  i++  )
        if ( svect[i] ) svect[i] = cvect[j++];
}

int ndv_reduce_vect_q(Q *svect,int trace,int col,IndArray *imat,NM_ind_pair *rp0,int nred)
{
    int i,j,k,len,pos,prev,nz;
    Q cs,mcs,c1,c2,cr,gcd,t;
    IndArray ivect;
    unsigned char *ivc;
    unsigned short *ivs;
    unsigned int *ivi;
    NDV redv;
    NMV mr;
    NODE rp;
    int maxrs;
    double hmag;
    Q *cvect;

    maxrs = 0;
    for ( i = 0; i < col && !svect[i]; i++ );
    if ( i == col ) return maxrs;
    hmag = p_mag((P)svect[i])*nd_scale;
    cvect = (Q *)ALLOCA(col*sizeof(Q));
    for ( i = 0; i < nred; i++ ) {
        ivect = imat[i];
        k = ivect->head;
        if ( svect[k] ) {
            maxrs = MAX(maxrs,rp0[i]->sugar);
            redv = trace?nd_ps_trace[rp0[i]->index]:nd_ps[rp0[i]->index];
            len = LEN(redv); mr = BDY(redv);
            igcd_cofactor(svect[k],CQ(mr),&gcd,&cs,&cr);
            chsgnq(cs,&mcs);
            if ( !UNIQ(cr) ) {
                for ( j = 0; j < col; j++ ) {
                    mulq(svect[j],cr,&c1); svect[j] = c1;
                }
            }
            svect[k] = 0; prev = k;
            switch ( ivect->width ) {
                case 1:
                    ivc = ivect->index.c;
                    for ( j = 1, NMV_ADV(mr); j < len; j++, NMV_ADV(mr) ) {
                        pos = prev+ivc[j]; prev = pos;
                        mulq(CQ(mr),mcs,&c2); addq(svect[pos],c2,&t); svect[pos] = t;
                    }
                    break;
                case 2:
                    ivs = ivect->index.s; 
                    for ( j = 1, NMV_ADV(mr); j < len; j++, NMV_ADV(mr) ) {
                        pos = prev+ivs[j]; prev = pos;
                        mulq(CQ(mr),mcs,&c2); addq(svect[pos],c2,&t); svect[pos] = t;
                    }
                    break;
                case 4:
                    ivi = ivect->index.i;
                    for ( j = 1, NMV_ADV(mr); j < len; j++, NMV_ADV(mr) ) {
                        pos = prev+ivi[j]; prev = pos;
                        mulq(CQ(mr),mcs,&c2); addq(svect[pos],c2,&t); svect[pos] = t;
                    }
                    break;
            }
            for ( j = k+1; j < col && !svect[j]; j++ );
            if ( j == col ) break;
            if ( hmag && ((double)p_mag((P)svect[j]) > hmag) ) {
                nz = compress_array(svect,cvect,col);
                removecont_array((P *)cvect,nz,1);
                expand_array(svect,cvect,nz);
                hmag = ((double)p_mag((P)svect[j]))*nd_scale;
            }
        }
    }
    nz = compress_array(svect,cvect,col);
    removecont_array((P *)cvect,nz,1);
    expand_array(svect,cvect,nz);
    if ( DP_Print ) { 
        fprintf(asir_out,"-"); fflush(asir_out);
    }
    return maxrs;
}

int ndv_reduce_vect(int m,UINT *svect,int col,IndArray *imat,NM_ind_pair *rp0,int nred)
{
    int i,j,k,len,pos,prev;
    UINT c,c1,c2,c3,up,lo,dmy;
    IndArray ivect;
    unsigned char *ivc;
    unsigned short *ivs;
    unsigned int *ivi;
    NDV redv;
    NMV mr;
    NODE rp;
    int maxrs;

    maxrs = 0;
    for ( i = 0; i < nred; i++ ) {
        ivect = imat[i];
        k = ivect->head; svect[k] %= m;
        if ( c = svect[k] ) {
            maxrs = MAX(maxrs,rp0[i]->sugar);
            c = m-c; redv = nd_ps[rp0[i]->index];
            len = LEN(redv); mr = BDY(redv);
            svect[k] = 0; prev = k;
            switch ( ivect->width ) {
                case 1:
                    ivc = ivect->index.c;
                    for ( j = 1, NMV_ADV(mr); j < len; j++, NMV_ADV(mr) ) {
                        pos = prev+ivc[j]; c1 = CM(mr); c2 = svect[pos];
                        prev = pos;
                        DMA(c1,c,c2,up,lo);
                        if ( up ) { DSAB(m,up,lo,dmy,c3); svect[pos] = c3;
                        } else svect[pos] = lo;
                    }
                    break;
                case 2:
                    ivs = ivect->index.s; 
                    for ( j = 1, NMV_ADV(mr); j < len; j++, NMV_ADV(mr) ) {
                        pos = prev+ivs[j]; c1 = CM(mr); c2 = svect[pos];
                        prev = pos;
                        DMA(c1,c,c2,up,lo);
                        if ( up ) { DSAB(m,up,lo,dmy,c3); svect[pos] = c3;
                        } else svect[pos] = lo;
                    }
                    break;
                case 4:
                    ivi = ivect->index.i;
                    for ( j = 1, NMV_ADV(mr); j < len; j++, NMV_ADV(mr) ) {
                        pos = prev+ivi[j]; c1 = CM(mr); c2 = svect[pos];
                        prev = pos;
                        DMA(c1,c,c2,up,lo);
                        if ( up ) { DSAB(m,up,lo,dmy,c3); svect[pos] = c3;
                        } else svect[pos] = lo;
                    }
                    break;
            }
        }
    }
    for ( i = 0; i < col; i++ )
        if ( svect[i] >= (UINT)m ) svect[i] %= m;
    return maxrs;
}

int ndv_reduce_vect_sf(int m,UINT *svect,int col,IndArray *imat,NM_ind_pair *rp0,int nred)
{
    int i,j,k,len,pos,prev;
    UINT c,c1,c2,c3,up,lo,dmy;
    IndArray ivect;
    unsigned char *ivc;
    unsigned short *ivs;
    unsigned int *ivi;
    NDV redv;
    NMV mr;
    NODE rp;
    int maxrs;

    maxrs = 0;
    for ( i = 0; i < nred; i++ ) {
        ivect = imat[i];
        k = ivect->head; svect[k] %= m;
        if ( c = svect[k] ) {
            maxrs = MAX(maxrs,rp0[i]->sugar);
            c = _chsgnsf(c); redv = nd_ps[rp0[i]->index];
            len = LEN(redv); mr = BDY(redv);
            svect[k] = 0; prev = k;
            switch ( ivect->width ) {
                case 1:
                    ivc = ivect->index.c;
                    for ( j = 1, NMV_ADV(mr); j < len; j++, NMV_ADV(mr) ) {
                        pos = prev+ivc[j]; prev = pos;
                        svect[pos] = _addsf(_mulsf(CM(mr),c),svect[pos]);
                    }
                    break;
                case 2:
                    ivs = ivect->index.s; 
                    for ( j = 1, NMV_ADV(mr); j < len; j++, NMV_ADV(mr) ) {
                        pos = prev+ivs[j]; prev = pos;
                        svect[pos] = _addsf(_mulsf(CM(mr),c),svect[pos]);
                    }
                    break;
                case 4:
                    ivi = ivect->index.i;
                    for ( j = 1, NMV_ADV(mr); j < len; j++, NMV_ADV(mr) ) {
                        pos = prev+ivi[j]; prev = pos;
                        svect[pos] = _addsf(_mulsf(CM(mr),c),svect[pos]);
                    }
                    break;
            }
        }
    }
    return maxrs;
}

NDV vect_to_ndv(UINT *vect,int spcol,int col,int *rhead,UINT *s0vect)
{
    int j,k,len;
    UINT *p;
    UINT c;
    NDV r;
    NMV mr0,mr;

    for ( j = 0, len = 0; j < spcol; j++ ) if ( vect[j] ) len++;
    if ( !len ) return 0;
    else {
        mr0 = (NMV)GC_malloc_atomic_ignore_off_page(nmv_adv*len);
#if 0
        ndv_alloc += nmv_adv*len;
#endif
        mr = mr0; 
        p = s0vect;
        for ( j = k = 0; j < col; j++, p += nd_wpd )
            if ( !rhead[j] ) {
                if ( c = vect[k++] ) {
                    ndl_copy(p,DL(mr)); CM(mr) = c; NMV_ADV(mr);
                }
            }
        MKNDV(nd_nvar,mr0,len,r);
        return r;
    }
}

/* for preprocessed vector */

NDV vect_to_ndv_q(Q *vect,int spcol,int col,int *rhead,UINT *s0vect)
{
    int j,k,len;
    UINT *p;
    Q c;
    NDV r;
    NMV mr0,mr;

    for ( j = 0, len = 0; j < spcol; j++ ) if ( vect[j] ) len++;
    if ( !len ) return 0;
    else {
        mr0 = (NMV)GC_malloc(nmv_adv*len);
#if 0
        ndv_alloc += nmv_adv*len;
#endif
        mr = mr0; 
        p = s0vect;
        for ( j = k = 0; j < col; j++, p += nd_wpd )
            if ( !rhead[j] ) {
                if ( c = vect[k++] ) {
                    if ( DN(c) )
                        error("afo");
                    ndl_copy(p,DL(mr)); CQ(mr) = c; NMV_ADV(mr);
                }
            }
        MKNDV(nd_nvar,mr0,len,r);
        return r;
    }
}

/* for plain vector */

NDV plain_vect_to_ndv_q(Q *vect,int col,UINT *s0vect)
{
    int j,k,len;
    UINT *p;
    Q c;
    NDV r;
    NMV mr0,mr;

    for ( j = 0, len = 0; j < col; j++ ) if ( vect[j] ) len++;
    if ( !len ) return 0;
    else {
        mr0 = (NMV)GC_malloc(nmv_adv*len);
#if 0
        ndv_alloc += nmv_adv*len;
#endif
        mr = mr0; 
        p = s0vect;
        for ( j = k = 0; j < col; j++, p += nd_wpd, k++ )
            if ( c = vect[k] ) {
                if ( DN(c) )
                    error("afo");
                ndl_copy(p,DL(mr)); CQ(mr) = c; NMV_ADV(mr);
            }
        MKNDV(nd_nvar,mr0,len,r);
        return r;
    }
}

int nd_sp_f4(int m,int trace,ND_pairs l,PGeoBucket bucket)
{
    ND_pairs t;
    NODE sp0,sp;
    int stat;
    ND spol;

    for ( t = l; t; t = NEXT(t) ) {
        stat = nd_sp(m,trace,t,&spol);
        if ( !stat ) return 0;
        if ( spol ) {
            add_pbucket_symbolic(bucket,spol);
        }
    }
    return 1;
}

int nd_symbolic_preproc(PGeoBucket bucket,int trace,UINT **s0vect,NODE *r)
{
    NODE rp0,rp;
    NM mul,head,s0,s;
    int index,col,i,sugar;
    RHist h;
    UINT *s0v,*p;
    NM_ind_pair pair;
    ND red;
    NDV *ps;

    s0 = 0; rp0 = 0; col = 0;
    ps = trace?nd_ps_trace:nd_ps;
    while ( 1 ) {
        head = remove_head_pbucket_symbolic(bucket);
        if ( !head ) break;
        if ( !s0 ) s0 = head;
        else NEXT(s) = head;
        s = head;
        index = ndl_find_reducer(DL(head));
        if ( index >= 0 ) {
            h = nd_psh[index];
            NEWNM(mul);
            ndl_sub(DL(head),DL(h),DL(mul));
            if ( ndl_check_bound2(index,DL(mul)) ) return 0;
            sugar = TD(DL(mul))+SG(ps[index]);
            MKNM_ind_pair(pair,mul,index,sugar);
            red = ndv_mul_nm_symbolic(mul,ps[index]);
            add_pbucket_symbolic(bucket,nd_remove_head(red));
            NEXTNODE(rp0,rp); BDY(rp) = (pointer)pair;
        }
        col++;
    }
    if ( rp0 ) NEXT(rp) = 0;
    NEXT(s) = 0;
    s0v = (UINT *)MALLOC_ATOMIC(col*nd_wpd*sizeof(UINT));
    for ( i = 0, p = s0v, s = s0; i < col;
        i++, p += nd_wpd, s = NEXT(s) ) ndl_copy(DL(s),p);
    *s0vect = s0v;        
    *r = rp0;
    return col;
}

NODE nd_f4(int m,int **indp)
{
    int i,nh,stat,index;
    NODE r,g;
    ND_pairs d,l,t;
    ND spol,red;
    NDV nf,redv;
    NM s0,s;
    NODE rp0,srp0,nflist;
    int nsp,nred,col,rank,len,k,j,a;
    UINT c;
    UINT **spmat;
    UINT *s0vect,*svect,*p,*v;
    int *colstat;
    IndArray *imat;
    int *rhead;
    int spcol,sprow;
    int sugar;
    PGeoBucket bucket;
    struct oEGT eg0,eg1,eg_f4;

#if 0
    ndv_alloc = 0;
#endif
    g = 0; d = 0;
    for ( i = 0; i < nd_psn; i++ ) {
        d = update_pairs(d,g,i,0);
        g = update_base(g,i);
    }
    while ( d ) {
        get_eg(&eg0);
        l = nd_minsugarp(d,&d);
        sugar = SG(l);
        bucket = create_pbucket();
        stat = nd_sp_f4(m,0,l,bucket);
        if ( !stat ) {
            for ( t = l; NEXT(t); t = NEXT(t) );
            NEXT(t) = d; d = l;
            d = nd_reconstruct(0,d);
            continue;
        }
        if ( bucket->m < 0 ) continue;
        col = nd_symbolic_preproc(bucket,0,&s0vect,&rp0);
        if ( !col ) {
            for ( t = l; NEXT(t); t = NEXT(t) );
            NEXT(t) = d; d = l;
            d = nd_reconstruct(0,d);
            continue;
        }
        get_eg(&eg1); init_eg(&eg_f4); add_eg(&eg_f4,&eg0,&eg1);
        if ( DP_Print )
            fprintf(asir_out,"sugar=%d,symb=%fsec,",
                sugar,eg_f4.exectime+eg_f4.gctime);
        if ( 1 )
            nflist = nd_f4_red(m,l,0,s0vect,col,rp0,0);
        else
            nflist = nd_f4_red_dist(m,l,s0vect,col,rp0,0);
        /* adding new bases */
        for ( r = nflist; r; r = NEXT(r) ) {
            nf = (NDV)BDY(r);
            ndv_removecont(m,nf);
            if ( !m && nd_nalg ) {
                ND nf1;

                nf1 = ndvtond(m,nf);
                nd_monic(0,&nf1);
                nd_removecont(m,nf1);
                nf = ndtondv(m,nf1);
            }
            nh = ndv_newps(m,nf,0);
            d = update_pairs(d,g,nh,0);
            g = update_base(g,nh);
        }
    }
#if 0
    fprintf(asir_out,"ndv_alloc=%d\n",ndv_alloc);
#endif
	conv_ilist(0,0,g,indp);
    return g;
}

NODE nd_f4_trace(int m,int **indp)
{
    int i,nh,stat,index;
    NODE r,g;
    ND_pairs d,l,l0,t;
    ND spol,red;
    NDV nf,redv,nfqv,nfv;
    NM s0,s;
    NODE rp0,srp0,nflist;
    int nsp,nred,col,rank,len,k,j,a;
    UINT c;
    UINT **spmat;
    UINT *s0vect,*svect,*p,*v;
    int *colstat;
    IndArray *imat;
    int *rhead;
    int spcol,sprow;
    int sugar;
    PGeoBucket bucket;
    struct oEGT eg0,eg1,eg_f4;

    g = 0; d = 0;
    for ( i = 0; i < nd_psn; i++ ) {
        d = update_pairs(d,g,i,0);
        g = update_base(g,i);
    }
    while ( d ) {
        get_eg(&eg0);
        l = nd_minsugarp(d,&d);
        sugar = SG(l);
        bucket = create_pbucket();
        stat = nd_sp_f4(m,0,l,bucket);
        if ( !stat ) {
            for ( t = l; NEXT(t); t = NEXT(t) );
            NEXT(t) = d; d = l;
            d = nd_reconstruct(1,d);
            continue;
        }
        if ( bucket->m < 0 ) continue;
        col = nd_symbolic_preproc(bucket,0,&s0vect,&rp0);
        if ( !col ) {
            for ( t = l; NEXT(t); t = NEXT(t) );
            NEXT(t) = d; d = l;
            d = nd_reconstruct(1,d);
            continue;
        }
        get_eg(&eg1); init_eg(&eg_f4); add_eg(&eg_f4,&eg0,&eg1);
        if ( DP_Print )
            fprintf(asir_out,"sugar=%d,symb=%fsec,",
                sugar,eg_f4.exectime+eg_f4.gctime);
        nflist = nd_f4_red(m,l,0,s0vect,col,rp0,&l0);
        if ( !l0 ) continue;
        l = l0;

        /* over Q */
        bucket = create_pbucket();
        stat = nd_sp_f4(0,1,l,bucket);
        if ( !stat ) {
            for ( t = l; NEXT(t); t = NEXT(t) );
            NEXT(t) = d; d = l;
            d = nd_reconstruct(1,d);
            continue;
        }
        if ( bucket->m < 0 ) continue;
        col = nd_symbolic_preproc(bucket,1,&s0vect,&rp0);
        if ( !col ) {
            for ( t = l; NEXT(t); t = NEXT(t) );
            NEXT(t) = d; d = l;
            d = nd_reconstruct(1,d);
            continue;
        }
        nflist = nd_f4_red(0,l,1,s0vect,col,rp0,0);
        /* adding new bases */
        for ( r = nflist; r; r = NEXT(r) ) {
            nfqv = (NDV)BDY(r);
            ndv_removecont(0,nfqv);
            if ( !rem(NM(HCQ(nfqv)),m) ) return 0;
            if ( nd_nalg ) {
                ND nf1;

                nf1 = ndvtond(m,nfqv);
                nd_monic(0,&nf1);
                nd_removecont(0,nf1);
                nfqv = ndtondv(0,nf1); nd_free(nf1);
            }
            nfv = ndv_dup(0,nfqv);
            ndv_mod(m,nfv);
            ndv_removecont(m,nfv);
            nh = ndv_newps(0,nfv,nfqv);
            d = update_pairs(d,g,nh,0);
            g = update_base(g,nh);
        }
    }
#if 0
    fprintf(asir_out,"ndv_alloc=%d\n",ndv_alloc);
#endif
	conv_ilist(0,1,g,indp);
    return g;
}

NODE nd_f4_red(int m,ND_pairs sp0,int trace,UINT *s0vect,int col,NODE rp0,ND_pairs *nz)
{
    IndArray *imat;
    int nsp,nred,i;
    int *rhead;
    NODE r0,rp;
    ND_pairs sp;
    NM_ind_pair *rvect;

    for ( sp = sp0, nsp = 0; sp; sp = NEXT(sp), nsp++ );
    nred = length(rp0);
    imat = (IndArray *)ALLOCA(nred*sizeof(IndArray));
    rhead = (int *)ALLOCA(col*sizeof(int));
    for ( i = 0; i < col; i++ ) rhead[i] = 0;

    /* construction of index arrays */
    rvect = (NM_ind_pair *)ALLOCA(nred*sizeof(NM_ind_pair));
    for ( rp = rp0, i = 0; rp; i++, rp = NEXT(rp) ) {
        rvect[i] = (NM_ind_pair)BDY(rp);
        imat[i] = nm_ind_pair_to_vect_compress(m,s0vect,col,rvect[i]);
        rhead[imat[i]->head] = 1;
    }
    if ( m )
        r0 = nd_f4_red_main(m,sp0,nsp,s0vect,col,rvect,rhead,imat,nred,nz);
    else
        r0 = nd_f4_red_q_main(sp0,nsp,trace,s0vect,col,rvect,rhead,imat,nred);
    return r0;
}

NODE nd_f4_red_main(int m,ND_pairs sp0,int nsp,UINT *s0vect,int col,
        NM_ind_pair *rvect,int *rhead,IndArray *imat,int nred,ND_pairs *nz)
{
    int spcol,sprow,a;
    int i,j,k,l,rank;
    NODE r0,r;
    ND_pairs sp;
    ND spol;
    int **spmat;
    UINT *svect,*v;
    int *colstat;
    struct oEGT eg0,eg1,eg2,eg_f4,eg_f4_1,eg_f4_2;
    int maxrs;
    int *spsugar;
    ND_pairs *spactive;

    spcol = col-nred;
    get_eg(&eg0);
    /* elimination (1st step) */
    spmat = (int **)ALLOCA(nsp*sizeof(UINT *));
    svect = (UINT *)ALLOCA(col*sizeof(UINT));
    spsugar = (int *)ALLOCA(nsp*sizeof(UINT));
    spactive = !nz?0:(ND_pairs *)ALLOCA(nsp*sizeof(ND_pairs));
    for ( a = sprow = 0, sp = sp0; a < nsp; a++, sp = NEXT(sp) ) {
        nd_sp(m,0,sp,&spol);
        if ( !spol ) continue;
        nd_to_vect(m,s0vect,col,spol,svect);
        if ( m == -1 ) 
            maxrs = ndv_reduce_vect_sf(m,svect,col,imat,rvect,nred);
        else
            maxrs = ndv_reduce_vect(m,svect,col,imat,rvect,nred);
        for ( i = 0; i < col; i++ ) if ( svect[i] ) break;
        if ( i < col ) {
            spmat[sprow] = v = (UINT *)MALLOC_ATOMIC(spcol*sizeof(UINT));
            for ( j = k = 0; j < col; j++ )
                if ( !rhead[j] ) v[k++] = svect[j];
            spsugar[sprow] = MAX(maxrs,SG(spol));
            if ( nz )
            spactive[sprow] = sp;
            sprow++;
        }
        nd_free(spol);
    }
    get_eg(&eg1); init_eg(&eg_f4_1); add_eg(&eg_f4_1,&eg0,&eg1);
    if ( DP_Print ) {
        fprintf(asir_out,"elim1=%fsec,",eg_f4_1.exectime+eg_f4_1.gctime);
        fflush(asir_out);
    }
    /* free index arrays */
    for ( i = 0; i < nred; i++ ) GC_free(imat[i]->index.c);

    /* elimination (2nd step) */
    colstat = (int *)ALLOCA(spcol*sizeof(int));
    if ( m == -1 )
        rank = nd_gauss_elim_sf(spmat,spsugar,sprow,spcol,m,colstat);
    else
        rank = nd_gauss_elim_mod(spmat,spsugar,spactive,sprow,spcol,m,colstat);
    r0 = 0;
    for ( i = 0; i < rank; i++ ) {
        NEXTNODE(r0,r); BDY(r) = 
            (pointer)vect_to_ndv(spmat[i],spcol,col,rhead,s0vect);
        SG((NDV)BDY(r)) = spsugar[i];
        GC_free(spmat[i]);
    }
    if ( r0 ) NEXT(r) = 0;

    for ( ; i < sprow; i++ ) GC_free(spmat[i]);
    get_eg(&eg2); init_eg(&eg_f4_2); add_eg(&eg_f4_2,&eg1,&eg2);
    init_eg(&eg_f4); add_eg(&eg_f4,&eg0,&eg2);
    if ( DP_Print ) {
        fprintf(asir_out,"elim2=%fsec\n",eg_f4_2.exectime+eg_f4_2.gctime);
        fprintf(asir_out,"nsp=%d,nred=%d,spmat=(%d,%d),rank=%d  ",
            nsp,nred,sprow,spcol,rank);
        fprintf(asir_out,"%fsec\n",eg_f4.exectime+eg_f4.gctime);
    }
    if ( nz ) {
        for ( i = 0; i < rank-1; i++ ) NEXT(spactive[i]) = spactive[i+1];
        if ( rank > 0 ) {
            NEXT(spactive[rank-1]) = 0;
            *nz = spactive[0];
        } else
            *nz = 0;
    }
    return r0;
}

#if 1
NODE nd_f4_red_q_main(ND_pairs sp0,int nsp,int trace,UINT *s0vect,int col,
        NM_ind_pair *rvect,int *rhead,IndArray *imat,int nred)
{
    int spcol,sprow,a;
    int i,j,k,l,rank;
    NODE r0,r;
    ND_pairs sp;
    ND spol;
    Q **spmat;
    Q *svect,*v;
    int *colstat;
    struct oEGT eg0,eg1,eg2,eg_f4,eg_f4_1,eg_f4_2;
    int maxrs;
    int *spsugar;
    pointer *w;

    spcol = col-nred;
    get_eg(&eg0);
    /* elimination (1st step) */
    spmat = (Q **)ALLOCA(nsp*sizeof(Q *));
    svect = (Q *)ALLOCA(col*sizeof(Q));
    spsugar = (int *)ALLOCA(nsp*sizeof(Q));
    for ( a = sprow = 0, sp = sp0; a < nsp; a++, sp = NEXT(sp) ) {
        nd_sp(0,trace,sp,&spol);
        if ( !spol ) continue;
        nd_to_vect_q(s0vect,col,spol,svect);
        maxrs = ndv_reduce_vect_q(svect,trace,col,imat,rvect,nred);
        for ( i = 0; i < col; i++ ) if ( svect[i] ) break;
        if ( i < col ) {
            spmat[sprow] = v = (Q *)MALLOC(spcol*sizeof(Q));
            for ( j = k = 0; j < col; j++ )
                if ( !rhead[j] ) v[k++] = svect[j];
            spsugar[sprow] = MAX(maxrs,SG(spol));
            sprow++;
        }
/*        nd_free(spol); */
    }
    get_eg(&eg1); init_eg(&eg_f4_1); add_eg(&eg_f4_1,&eg0,&eg1);
    if ( DP_Print ) {
        fprintf(asir_out,"elim1=%fsec,",eg_f4_1.exectime+eg_f4_1.gctime);
        fflush(asir_out);
    }
    /* free index arrays */
/*    for ( i = 0; i < nred; i++ ) GC_free(imat[i]->index.c); */

    /* elimination (2nd step) */
    colstat = (int *)ALLOCA(spcol*sizeof(int));
    rank = nd_gauss_elim_q(spmat,spsugar,sprow,spcol,colstat);
    w = (pointer *)ALLOCA(rank*sizeof(pointer));
    for ( i = 0; i < rank; i++ ) {
        w[rank-i-1] = (pointer)vect_to_ndv_q(spmat[i],spcol,col,rhead,s0vect);
        SG((NDV)w[rank-i-1]) = spsugar[i];
/*        GC_free(spmat[i]); */
    }
#if 0
    qsort(w,rank,sizeof(NDV),
        (int (*)(const void *,const void *))ndv_compare);
#endif
    r0 = 0;
    for ( i = 0; i < rank; i++ ) {
        NEXTNODE(r0,r); BDY(r) = w[i];
    }
    if ( r0 ) NEXT(r) = 0;

/*    for ( ; i < sprow; i++ ) GC_free(spmat[i]); */
    get_eg(&eg2); init_eg(&eg_f4_2); add_eg(&eg_f4_2,&eg1,&eg2);
    init_eg(&eg_f4); add_eg(&eg_f4,&eg0,&eg2);
    if ( DP_Print ) {
        fprintf(asir_out,"elim2=%fsec\n",eg_f4_2.exectime+eg_f4_2.gctime);
        fprintf(asir_out,"nsp=%d,nred=%d,spmat=(%d,%d),rank=%d  ",
            nsp,nred,sprow,spcol,rank);
        fprintf(asir_out,"%fsec\n",eg_f4.exectime+eg_f4.gctime);
    }
    return r0;
}
#else
void printm(Q **mat,int row,int col)
{
    int i,j;
    printf("[");
    for ( i = 0; i < row; i++ ) {
        for ( j = 0; j < col; j++ ) {
            printexpr(CO,mat[i][j]); printf(" ");
        }
        printf("]\n");
    }
}

NODE nd_f4_red_q_main(ND_pairs sp0,int nsp,UINT *s0vect,int col,
        NM_ind_pair *rvect,int *rhead,IndArray *imat,int nred)
{
    int row,a;
    int i,j,rank;
    NODE r0,r;
    ND_pairs sp;
    ND spol;
    Q **mat;
    int *colstat;
    int *sugar;

    row = nsp+nred;
    /* make the matrix */
    mat = (Q **)ALLOCA(row*sizeof(Q *));
    sugar = (int *)ALLOCA(row*sizeof(int));
    for ( row = a = 0, sp = sp0; a < nsp; a++, sp = NEXT(sp) ) {
        nd_sp(0,0,sp,&spol);
        if ( !spol ) continue;
        mat[row] = (Q *)MALLOC(col*sizeof(Q));
        nd_to_vect_q(s0vect,col,spol,mat[row]);
        sugar[row] = SG(spol);
        row++;
    }
    for ( i = 0; i < nred; i++, row++ ) {
        mat[row] = nm_ind_pair_to_vect(0,s0vect,col,rvect[i]);
        sugar[row] = rvect[i]->sugar;
    }
    /* elimination */
    colstat = (int *)ALLOCA(col*sizeof(int));
    rank = nd_gauss_elim_q(mat,sugar,row,col,colstat);
    r0 = 0;
    for ( i = 0; i < rank; i++ ) {
        for ( j = 0; j < col; j++ ) if ( mat[i][j] ) break;
        if ( j == col ) error("nd_f4_red_q_main : cannot happen");
        if ( rhead[j] ) continue;
        NEXTNODE(r0,r); BDY(r) = 
            (pointer)plain_vect_to_ndv_q(mat[i],col,s0vect);
        SG((NDV)BDY(r)) = sugar[i];
    }
    if ( r0 ) NEXT(r) = 0;
    printf("\n");
    return r0;
}
#endif

FILE *nd_write,*nd_read;

void nd_send_int(int a) {
    write_int(nd_write,&a);
}

void nd_send_intarray(int *p,int len) {
    write_intarray(nd_write,p,len);
}

int nd_recv_int() {
    int a;

    read_int(nd_read,&a);
    return a;
}

void nd_recv_intarray(int *p,int len) {
    read_intarray(nd_read,p,len);
}

void nd_send_ndv(NDV p) {
    int len,i;
    NMV m;

    if ( !p ) nd_send_int(0);
    else {
        len = LEN(p);
        nd_send_int(len);
        m = BDY(p);
        for ( i = 0; i < len; i++, NMV_ADV(m) ) {
            nd_send_int(CM(m));    
            nd_send_intarray(DL(m),nd_wpd);
        }
    }
}

void nd_send_nd(ND p) {
    int len,i;
    NM m;

    if ( !p ) nd_send_int(0);
    else {
        len = LEN(p);
        nd_send_int(len);
        m = BDY(p);
        for ( i = 0; i < len; i++, m = NEXT(m) ) {
            nd_send_int(CM(m));    
            nd_send_intarray(DL(m),nd_wpd);
        }
    }
}

NDV nd_recv_ndv()
{
    int len,i;
    NMV m,m0;
    NDV r;

    len = nd_recv_int();
    if ( !len ) return 0;
    else {
        m0 = m = (NMV)GC_malloc_atomic_ignore_off_page(nmv_adv*len);
#if 0
        ndv_alloc += len*nmv_adv;
#endif
        for ( i = 0; i < len; i++, NMV_ADV(m) ) {
            CM(m) = nd_recv_int();    
            nd_recv_intarray(DL(m),nd_wpd);
        }
        MKNDV(nd_nvar,m0,len,r);
        return r;    
    }
}

int ox_exec_f4_red(Q proc)
{
    Obj obj;
    STRING fname;
    NODE arg;
    int s;
    extern int ox_need_conv,ox_file_io;

    MKSTR(fname,"nd_exec_f4_red");
    arg = mknode(2,proc,fname);
    Pox_cmo_rpc(arg,&obj);
    s = get_ox_server_id(QTOS(proc));
    nd_write = iofp[s].out;
    nd_read = iofp[s].in;
    ox_need_conv = ox_file_io = 0;
    return s;
}

NODE nd_f4_red_dist(int m,ND_pairs sp0,UINT *s0vect,int col,NODE rp0,ND_pairs *nz)
{
    int nsp,nred;
    int i,rank,s;
    NODE rp,r0,r;
    ND_pairs sp;
    NM_ind_pair pair;
    NMV nmv;
    NM nm;
    NDV nf;
    Obj proc,dmy;

    ox_launch_main(0,0,&proc);
    s = ox_exec_f4_red((Q)proc);

    nd_send_int(m);
    nd_send_int(nd_nvar);
    nd_send_int(nd_bpe);
    nd_send_int(nd_wpd);
    nd_send_int(nmv_adv);

    saveobj(nd_write,dp_current_spec->obj); fflush(nd_write);

    nd_send_int(nd_psn);
    for ( i = 0; i < nd_psn; i++ ) nd_send_ndv(nd_ps[i]);

    for ( sp = sp0, nsp = 0; sp; sp = NEXT(sp), nsp++ );
    nd_send_int(nsp);
    for ( i = 0, sp = sp0; i < nsp; i++, sp = NEXT(sp) ) {
        nd_send_int(sp->i1); nd_send_int(sp->i2);
    }

    nd_send_int(col); nd_send_intarray(s0vect,col*nd_wpd);

    nred = length(rp0); nd_send_int(nred);
    for ( i = 0, rp = rp0; i < nred; i++, rp = NEXT(rp) ) {
        pair = (NM_ind_pair)BDY(rp);
        nd_send_int(pair->index);
        nd_send_intarray(pair->mul->dl,nd_wpd);
    }
    fflush(nd_write);
    rank = nd_recv_int();
    fprintf(asir_out,"rank=%d\n",rank);
    r0 = 0;
    for ( i = 0; i < rank; i++ ) {
        nf = nd_recv_ndv();
        NEXTNODE(r0,r); BDY(r) = (pointer)nf;
    }
    Pox_shutdown(mknode(1,proc),&dmy);
    return r0;
}

/* server side */

void nd_exec_f4_red_dist()
{
    int m,i,nsp,col,s0size,nred,spcol,j,k;
    NM_ind_pair *rp0;
    NDV nf;
    UINT *s0vect;
    IndArray *imat;
    int *rhead;
    int **spmat;
    UINT *svect,*v;
    ND_pairs *sp0;
    int *colstat;
    int a,sprow,rank;
    struct order_spec *ord;
    Obj ordspec;
    ND spol;
    int maxrs;
    int *spsugar;

    nd_read = iofp[0].in;
    nd_write = iofp[0].out;
    m = nd_recv_int();
    nd_nvar = nd_recv_int();
    nd_bpe = nd_recv_int();
    nd_wpd = nd_recv_int();
    nmv_adv = nd_recv_int();

    loadobj(nd_read,&ordspec);
    create_order_spec(0,ordspec,&ord);
    nd_init_ord(ord);
    nd_setup_parameters(nd_nvar,0);

    nd_psn = nd_recv_int();
    nd_ps = (NDV *)MALLOC(nd_psn*sizeof(NDV));
    nd_bound = (UINT **)MALLOC(nd_psn*sizeof(UINT *));
    for ( i = 0; i < nd_psn; i++ ) {
        nd_ps[i] = nd_recv_ndv();
        nd_bound[i] = ndv_compute_bound(nd_ps[i]);
    }

    nsp = nd_recv_int();
    sp0 = (ND_pairs *)MALLOC(nsp*sizeof(ND_pairs));
    for ( i = 0; i < nsp; i++ ) {
        NEWND_pairs(sp0[i]);
        sp0[i]->i1 = nd_recv_int(); sp0[i]->i2 = nd_recv_int();
        ndl_lcm(HDL(nd_ps[sp0[i]->i1]),HDL(nd_ps[sp0[i]->i2]),LCM(sp0[i]));
    }

    col = nd_recv_int();
    s0size = col*nd_wpd;
    s0vect = (UINT *)MALLOC(s0size*sizeof(UINT));
    nd_recv_intarray(s0vect,s0size);

    nred = nd_recv_int();
    rp0 = (NM_ind_pair *)MALLOC(nred*sizeof(NM_ind_pair));
    for ( i = 0; i < nred; i++ ) {
        rp0[i] = (NM_ind_pair)MALLOC(sizeof(struct oNM_ind_pair));
        rp0[i]->index = nd_recv_int();
        rp0[i]->mul = (NM)MALLOC(sizeof(struct oNM)+(nd_wpd-1)*sizeof(UINT));
        nd_recv_intarray(rp0[i]->mul->dl,nd_wpd);
    }

    spcol = col-nred;
    imat = (IndArray *)MALLOC(nred*sizeof(IndArray));
    rhead = (int *)MALLOC(col*sizeof(int));
    for ( i = 0; i < col; i++ ) rhead[i] = 0;

    /* construction of index arrays */
    for ( i = 0; i < nred; i++ ) {
        imat[i] = nm_ind_pair_to_vect_compress(m,s0vect,col,rp0[i]);
        rhead[imat[i]->head] = 1;
    }

    /* elimination (1st step) */
    spmat = (int **)MALLOC(nsp*sizeof(UINT *));
    svect = (UINT *)MALLOC(col*sizeof(UINT));
    spsugar = (int *)ALLOCA(nsp*sizeof(UINT));
    for ( a = sprow = 0; a < nsp; a++ ) {
        nd_sp(m,0,sp0[a],&spol);
        if ( !spol ) continue;
        nd_to_vect(m,s0vect,col,spol,svect);
        if ( m == -1 ) 
            maxrs = ndv_reduce_vect_sf(m,svect,col,imat,rp0,nred);
        else 
            maxrs = ndv_reduce_vect(m,svect,col,imat,rp0,nred);
        for ( i = 0; i < col; i++ ) if ( svect[i] ) break;
        if ( i < col ) {
            spmat[sprow] = v = (UINT *)MALLOC(spcol*sizeof(UINT));
            for ( j = k = 0; j < col; j++ )
                if ( !rhead[j] ) v[k++] = svect[j];
            spsugar[sprow] = MAX(maxrs,SG(spol));
            sprow++;
        }
        nd_free(spol);
    }
    /* elimination (2nd step) */
    colstat = (int *)ALLOCA(spcol*sizeof(int));
    if ( m == -1 )
        rank = nd_gauss_elim_sf(spmat,spsugar,sprow,spcol,m,colstat);
    else
        rank = nd_gauss_elim_mod(spmat,spsugar,0,sprow,spcol,m,colstat);
    nd_send_int(rank);
    for ( i = 0; i < rank; i++ ) {
        nf = vect_to_ndv(spmat[i],spcol,col,rhead,s0vect);
        nd_send_ndv(nf);
    }
    fflush(nd_write);
}

int nd_gauss_elim_q(Q **mat0,int *sugar,int row,int col,int *colstat)
{
    int mod,i,j,t,c,rank,rank0,inv;
    int *ci,*ri;
    Q dn;
    MAT m,nm;
    int **wmat;

    /* XXX */
    mod = 99999989;
    wmat = (int **)ALLOCA(row*sizeof(int *));
    for ( i = 0; i < row; i++ ) {
        wmat[i] = (int *)ALLOCA(col*sizeof(int));
        for ( j = 0; j < col; j++ ) {
            if ( mat0[i][j] ) {
                t = rem(NM(mat0[i][j]),mod);
                if ( SGN(mat0[i][j]) < 0 ) t = mod-t;
                wmat[i][j] = t;
            } else
                wmat[i][j] = 0;
        }
    }
    rank0 = nd_gauss_elim_mod(wmat,sugar,0,row,col,mod,colstat);
    NEWMAT(m); m->row = row; m->col = col; m->body = (pointer **)mat0;
    rank = generic_gauss_elim(m,&nm,&dn,&ri,&ci);
    if ( rank != rank0 )
        error("afo");
    for ( i = 0; i < row; i++ )
        for ( j = 0; j < col; j++ )
            mat0[i][j] = 0;
    c = col-rank;
    for ( i = 0; i < rank; i++ ) {
        mat0[i][ri[i]] = dn;    
        for ( j = 0; j < c; j++ )
            mat0[i][ci[j]] = (Q)BDY(nm)[i][j];
    }
    inv = invm(rem(NM(dn),mod),mod);
    if ( SGN(dn) < 0 ) inv = mod-inv;
    for ( i = 0; i < row; i++ )
        for ( j = 0; j < col; j++ ) {
            if ( mat0[i][j] ) {
                t = rem(NM(mat0[i][j]),mod);
                if ( SGN(mat0[i][j]) < 0 ) t = mod-t;
            } else
                t = 0;
            c = dmar(t,inv,0,mod);
            if ( wmat[i][j] != c )
                error("afo");
        }
    return rank;
}

int nd_gauss_elim_mod(int **mat0,int *sugar,ND_pairs *spactive,int row,int col,int md,int *colstat)
{
    int i,j,k,l,inv,a,rank,s;
    unsigned int *t,*pivot,*pk;
    unsigned int **mat;
    ND_pairs pair;

    mat = (unsigned int **)mat0;
    for ( rank = 0, j = 0; j < col; j++ ) {
        for ( i = rank; i < row; i++ )
            mat[i][j] %= md;
        for ( i = rank; i < row; i++ )
            if ( mat[i][j] )
                break;
        if ( i == row ) {
            colstat[j] = 0;
            continue;
        } else
            colstat[j] = 1;
        if ( i != rank ) {
            t = mat[i]; mat[i] = mat[rank]; mat[rank] = t;
            s = sugar[i]; sugar[i] = sugar[rank]; sugar[rank] = s;
            if ( spactive ) {
                pair = spactive[i]; spactive[i] = spactive[rank]; 
                spactive[rank] = pair;
            }
        }
        pivot = mat[rank];
        s = sugar[rank];
        inv = invm(pivot[j],md);
        for ( k = j, pk = pivot+k; k < col; k++, pk++ )
            if ( *pk ) {
                if ( *pk >= (unsigned int)md )
                    *pk %= md;
                DMAR(*pk,inv,0,md,*pk)
            }
        for ( i = rank+1; i < row; i++ ) {
            t = mat[i];
            if ( a = t[j] ) {
                sugar[i] = MAX(sugar[i],s);
                red_by_vect(md,t+j,pivot+j,md-a,col-j);
            }
        }
        rank++;
    }
    for ( j = col-1, l = rank-1; j >= 0; j-- )
        if ( colstat[j] ) {
            pivot = mat[l];
            s = sugar[l];
            for ( i = 0; i < l; i++ ) {
                t = mat[i];
                t[j] %= md;
                if ( a = t[j] ) {
                    sugar[i] = MAX(sugar[i],s);
                    red_by_vect(md,t+j,pivot+j,md-a,col-j);
                }
            }
            l--;
        }
    for ( j = 0, l = 0; l < rank; j++ )
        if ( colstat[j] ) {
            t = mat[l];
            for ( k = j; k < col; k++ )
                if ( t[k] >= (unsigned int)md )
                    t[k] %= md;
            l++;
        }
    return rank;
}

int nd_gauss_elim_sf(int **mat0,int *sugar,int row,int col,int md,int *colstat)
{
    int i,j,k,l,inv,a,rank,s;
    unsigned int *t,*pivot,*pk;
    unsigned int **mat;

    mat = (unsigned int **)mat0;
    for ( rank = 0, j = 0; j < col; j++ ) {
        for ( i = rank; i < row; i++ )
            if ( mat[i][j] )
                break;
        if ( i == row ) {
            colstat[j] = 0;
            continue;
        } else
            colstat[j] = 1;
        if ( i != rank ) {
            t = mat[i]; mat[i] = mat[rank]; mat[rank] = t;
            s = sugar[i]; sugar[i] = sugar[rank]; sugar[rank] = s;
        }
        pivot = mat[rank];
        s = sugar[rank];
        inv = _invsf(pivot[j]);
        for ( k = j, pk = pivot+k; k < col; k++, pk++ )
            if ( *pk )
                *pk = _mulsf(*pk,inv);
        for ( i = rank+1; i < row; i++ ) {
            t = mat[i];
            if ( a = t[j] ) {
                sugar[i] = MAX(sugar[i],s);
                red_by_vect_sf(md,t+j,pivot+j,_chsgnsf(a),col-j);
            }
        }
        rank++;
    }
    for ( j = col-1, l = rank-1; j >= 0; j-- )
        if ( colstat[j] ) {
            pivot = mat[l];
            s = sugar[l];
            for ( i = 0; i < l; i++ ) {
                t = mat[i];
                if ( a = t[j] ) {
                    sugar[i] = MAX(sugar[i],s);
                    red_by_vect_sf(md,t+j,pivot+j,_chsgnsf(a),col-j);
                }
            }
            l--;
        }
    return rank;
}

int ndv_ishomo(NDV p)
{
    NMV m;
    int len,h;

    if ( !p ) return 1;
    len = LEN(p);
    m = BDY(p);
    h = TD(DL(m));
    NMV_ADV(m);
    for ( len--; len; len--, NMV_ADV(m) )
        if ( TD(DL(m)) != h ) return 0;
    return 1;
}

void ndv_save(NDV p,int index)
{
    FILE *s;
    char name[BUFSIZ];
    short id;
    int nv,sugar,len,n,i,td,e,j;
    NMV m;
    unsigned int *dl;
    int mpos;

    sprintf(name,"%s/%d",Demand,index);
    s = fopen(name,"w");
    savevl(s,0);
    if ( !p ) { 
        saveobj(s,0);
        return;
    }
    id = O_DP;
    nv = NV(p);
    sugar = SG(p);
    len = LEN(p);
    write_short(s,&id); write_int(s,&nv); write_int(s,&sugar);
    write_int(s,&len);

    for ( m = BDY(p), i = 0; i < len; i++, NMV_ADV(m) ) {
        saveobj(s,(Obj)CQ(m));
        dl = DL(m);
        td = TD(dl);
        write_int(s,&td);
        for ( j = 0; j < nv; j++ ) {
            e = GET_EXP(dl,j);    
            write_int(s,&e);
        }
        if ( nd_module ) {
            mpos = MPOS(dl); write_int(s,&mpos);
        }
    }
    fclose(s);
}

NDV ndv_load(int index)
{
    FILE *s;
    char name[BUFSIZ];
    short id;
    int nv,sugar,len,n,i,td,e,j;
    NDV d;
    NMV m0,m;
    unsigned int *dl;
    Obj obj;
    int mpos;

    sprintf(name,"%s/%d",Demand,index);
    s = fopen(name,"r");
    if ( !s ) return 0;

    skipvl(s);
    read_short(s,&id);
    if ( !id ) return 0;
    read_int(s,&nv);
    read_int(s,&sugar);
    read_int(s,&len);

    m0 = m = MALLOC(len*nmv_adv);
    for ( i = 0; i < len; i++, NMV_ADV(m) ) {
        loadobj(s,&obj); CQ(m) = (Q)obj;
        dl = DL(m);
        ndl_zero(dl);
        read_int(s,&td); TD(dl) = td;
        for ( j = 0; j < nv; j++ ) {
            read_int(s,&e);
            PUT_EXP(dl,j,e);    
        }
        if ( nd_module ) {
            read_int(s,&mpos); MPOS(dl) = mpos;
        }
        if ( nd_blockmask ) ndl_weight_mask(dl);
    }
    fclose(s);
    MKNDV(nv,m0,len,d);
    SG(d) = sugar;
    return d;
}

void nd_det(int mod,MAT f,P *rp)
{
    VL fv,tv;
    int n,i,j,max,e,nvar,sgn,k0,l0,len0,len,k,l,a;
    pointer **m;
    Q mone;
    P **w;
    P mp,r;
    NDV **dm;
    NDV *t,*mi,*mj;
    NDV d,s,mij,mjj;
    ND u;
    NMV nmv;
    UINT *bound;
    PGeoBucket bucket;
    struct order_spec *ord;
    Q dq,dt,ds;
    N gn,qn,dn0,nm,dn;

    create_order_spec(0,0,&ord);
    nd_init_ord(ord);
    get_vars((Obj)f,&fv);
    if ( f->row != f->col )
        error("nd_det : non-square matrix");
    n = f->row;
    m = f->body;
    for ( nvar = 0, tv = fv; tv; tv = NEXT(tv), nvar++ );

    if ( !nvar ) {
        if ( !mod )
            detp(CO,(P **)m,n,rp);
        else {
            w = (P **)almat_pointer(n,n);
            for ( i = 0; i < n; i++ )
                for ( j = 0; j < n; j++ )
                    ptomp(mod,(P)m[i][j],&w[i][j]);
            detmp(CO,mod,w,n,&mp);
            mptop(mp,rp);
        }
        return;
    }
    
    if ( !mod ) {
        w = (P **)almat_pointer(n,n);
        dq = ONE;
        for ( i = 0; i < n; i++ ) {
            dn0 = ONEN;
            for ( j = 0; j < n; j++ ) {
                if ( !m[i][j] ) continue;
                lgp(m[i][j],&nm,&dn);
                gcdn(dn0,dn,&gn); divsn(dn0,gn,&qn); muln(qn,dn,&dn0);
            }
            if ( !UNIN(dn0) ) {
                NTOQ(dn0,1,ds);
                for ( j = 0; j < n; j++ )
                    mulp(CO,(P)m[i][j],(P)ds,&w[i][j]);
                mulq(dq,ds,&dt); dq = dt;
            } else
                for ( j = 0; j < n; j++ )
                    w[i][j] = (P)m[i][j];
        }
        m = (pointer **)w;
    }

    for ( i = 0, max = 0; i < n; i++ )
        for ( j = 0; j < n; j++ )
            for ( tv = fv; tv; tv = NEXT(tv) ) {
                e = getdeg(tv->v,(P)m[i][j]);
                max = MAX(e,max);
            }
    nd_setup_parameters(nvar,max);
    dm = (NDV **)almat_pointer(n,n);
    for ( i = 0, max = 0; i < n; i++ )
        for ( j = 0; j < n; j++ ) {
            dm[i][j] = ptondv(CO,fv,m[i][j]);
            if ( mod ) ndv_mod(mod,dm[i][j]);
            if ( dm[i][j] && !LEN(dm[i][j]) ) dm[i][j] = 0;
        }
    d = ptondv(CO,fv,(P)ONE);
    if ( mod ) ndv_mod(mod,d);
    chsgnq(ONE,&mone);
    for ( j = 0, sgn = 1; j < n; j++ ) {
        if ( DP_Print ) fprintf(stderr,".",j);
        for ( i = j; i < n && !dm[i][j]; i++ );
        if ( i == n ) {
            *rp = 0;
            return;
        }
        k0 = i; l0 = j; len0 = LEN(dm[k0][l0]);
        for ( k = j; k < n; k++ )
            for ( l = j; l < n; l++ )
                if ( dm[k][l] && LEN(dm[k][l]) < len0 ) {
                    k0 = k; l0 = l; len0 = LEN(dm[k][l]);
                }
        if ( k0 != j ) {
            t = dm[j]; dm[j] = dm[k0]; dm[k0] = t;
            sgn = -sgn;
        }
        if ( l0 != j ) {
            for ( k = j; k < n; k++ ) {
                s = dm[k][j]; dm[k][j] = dm[k][l0]; dm[k][l0] = s;
            }
            sgn = -sgn;
        }
        bound = nd_det_compute_bound(dm,n,j);
        for ( k = 0; k < nd_nvar; k++ )
            if ( bound[k]*2 > nd_mask0 ) break;
        if ( k < nd_nvar )
            nd_det_reconstruct(dm,n,j,d);

        for ( i = j+1, mj = dm[j], mjj = mj[j]; i < n; i++ ) {
/*            if ( DP_Print ) fprintf(stderr,"    i=%d\n        ",i); */
            mi = dm[i]; mij = mi[j];
            if ( mod )
                ndv_mul_c(mod,mij,mod-1);
            else
                ndv_mul_c_q(mij,mone);
            for ( k = j+1; k < n; k++ ) {
/*                if ( DP_Print ) fprintf(stderr,"k=%d ",k); */
                bucket = create_pbucket();
                if ( mi[k] ) {
                    nmv = BDY(mjj); len = LEN(mjj);
                    for ( a = 0; a < len; a++, NMV_ADV(nmv) ) {
                        u = ndv_mul_nmv_trunc(mod,nmv,mi[k],DL(BDY(d)));
                        add_pbucket(mod,bucket,u);
                    }
                }
                if ( mj[k] && mij ) {
                    nmv = BDY(mij); len = LEN(mij);
                    for ( a = 0; a < len; a++, NMV_ADV(nmv) ) {
                        u = ndv_mul_nmv_trunc(mod,nmv,mj[k],DL(BDY(d)));
                        add_pbucket(mod,bucket,u);
                    }
                }
                u = nd_quo(mod,bucket,d);
                mi[k] = ndtondv(mod,u);
            }
/*            if ( DP_Print ) fprintf(stderr,"\n",k); */
        }
        d = mjj;
    }
    if ( DP_Print ) fprintf(stderr,"\n",k);
    if ( sgn < 0 )
        if ( mod )
            ndv_mul_c(mod,d,mod-1);
        else
            ndv_mul_c_q(d,mone);
    r = ndvtop(mod,CO,fv,d);
    if ( !mod && !UNIQ(dq) )
        divsp(CO,r,(P)dq,rp);
    else
        *rp = r;
}

ND ndv_mul_nmv_trunc(int mod,NMV m0,NDV p,UINT *d)
{
    NM mr,mr0;
    NM tnm;
    NMV m;
    UINT *d0,*dt,*dm;
    int c,n,td,i,c1,c2,len;
    Q q;
    ND r;

    if ( !p ) return 0;
    else {
        n = NV(p); m = BDY(p); len = LEN(p);
        d0 = DL(m0);
        td = TD(d);
        mr0 = 0;
        NEWNM(tnm);
        if ( mod ) {
            c = CM(m0);
            for ( i = 0; i < len; i++, NMV_ADV(m) ) {
                ndl_add(DL(m),d0,DL(tnm));
                if ( ndl_reducible(DL(tnm),d) ) {
                    NEXTNM(mr0,mr);
                    c1 = CM(m); DMAR(c1,c,0,mod,c2); CM(mr) = c2;
                    ndl_copy(DL(tnm),DL(mr));
                }
            }
        } else {
            q = CQ(m0);
            for ( i = 0; i < len; i++, NMV_ADV(m) ) {
                ndl_add(DL(m),d0,DL(tnm));
                if ( ndl_reducible(DL(tnm),d) ) {
                    NEXTNM(mr0,mr);
                    mulq(CQ(m),q,&CQ(mr));
                    ndl_copy(DL(tnm),DL(mr));
                }
            }
        }
        if ( !mr0 )
            return 0;
        else {
            NEXT(mr) = 0; 
            for ( len = 0, mr = mr0; mr; mr = NEXT(mr), len++ );
            MKND(NV(p),mr0,len,r);
            SG(r) = SG(p) + TD(d0);
            return r;
        }
    }
}

void nd_det_reconstruct(NDV **dm,int n,int j,NDV d)
{
    int i,obpe,oadv,h,k,l;
    static NM prev_nm_free_list;
    EPOS oepos;

    obpe = nd_bpe;
    oadv = nmv_adv;
    oepos = nd_epos;
    if ( obpe < 2 ) nd_bpe = 2;
    else if ( obpe < 3 ) nd_bpe = 3;
    else if ( obpe < 4 ) nd_bpe = 4;
    else if ( obpe < 5 ) nd_bpe = 5;
    else if ( obpe < 6 ) nd_bpe = 6;
    else if ( obpe < 8 ) nd_bpe = 8;
    else if ( obpe < 10 ) nd_bpe = 10;
    else if ( obpe < 16 ) nd_bpe = 16;
    else if ( obpe < 32 ) nd_bpe = 32;
    else error("nd_det_reconstruct : exponent too large");

    nd_setup_parameters(nd_nvar,0);
    prev_nm_free_list = _nm_free_list;
    _nm_free_list = 0;
    for ( k = j; k < n; k++ )
        for (l = j; l < n; l++ )
            ndv_realloc(dm[k][l],obpe,oadv,oepos);
    ndv_realloc(d,obpe,oadv,oepos);
    prev_nm_free_list = 0;
#if 0
    GC_gcollect();
#endif
}

/* returns a UINT array containing degree bounds */

UINT *nd_det_compute_bound(NDV **dm,int n,int j)
{
    UINT *d0,*d1,*d,*t,*r;
    int k,l,i;

    d0 = (UINT *)MALLOC(nd_nvar*sizeof(UINT));
    for ( k = 0; k < nd_nvar; k++ ) d0[k] = 0;
    for ( k = j; k < n; k++ )
        for ( l = j; l < n; l++ )
            if ( dm[k][l] ) {
                d = ndv_compute_bound(dm[k][l]);
                for ( i = 0; i < nd_nvar; i++ )
                    d0[i] = MAX(d0[i],d[i]);
            }
    return d0;
}

DL nd_separate_d(UINT *d,UINT *trans)
{
    int n,td,i,e,j;
    DL a;

    ndl_zero(trans);
    td = 0;
    for ( i = 0; i < nd_ntrans; i++ ) {
        e = GET_EXP(d,i);
        PUT_EXP(trans,i,e);
        td += MUL_WEIGHT(e,i);
    }
    if ( nd_ntrans+nd_nalg < nd_nvar ) {
        /* homogenized */
        i = nd_nvar-1;
        e = GET_EXP(d,i);
        PUT_EXP(trans,i,e);
        td += MUL_WEIGHT(e,i);
    }
    TD(trans) = td;
    if ( nd_blockmask) ndl_weight_mask(trans);
    NEWDL(a,nd_nalg);
    td = 0;
    for ( i = 0; i < nd_nalg; i++ ) {
        j = nd_ntrans+i;
        e = GET_EXP(d,j);
        a->d[i] = e;
        td += e;
    }
    a->td = td;
    return a;
}

int nd_monic(int mod,ND *p)
{
    UINT *trans,*t;
    DL alg;
    MP mp0,mp;
    NM m,m0,m1,ma0,ma,mb,mr0,mr;
    ND r;
    DL dl;
    DP nm;
    NDV ndv;
    DAlg inv,cd;
    ND s,c;
    Q l,mul;
    N ln;
    int n,ntrans,i,e,td,is_lc,len;
    NumberField nf;
    struct oEGT eg0,eg1;

    if ( !(nf = get_numberfield()) )
        error("nd_monic : current_numberfield is not set");

    /* Q coef -> DAlg coef */
    NEWNM(ma0); ma = ma0;
    m = BDY(*p); 
    is_lc = 1;
    while ( 1 ) {
        NEWMP(mp0); mp = mp0;
        mp->c = (P)CQ(m);
        mp->dl = nd_separate_d(DL(m),DL(ma));
        NEWNM(mb);
        for ( m = NEXT(m); m; m = NEXT(m) ) {
            alg = nd_separate_d(DL(m),DL(mb));
            if ( !ndl_equal(DL(ma),DL(mb)) )
                break;
            NEXTMP(mp0,mp); mp->c = (P)CQ(m); mp->dl = alg;
        }
        NEXT(mp) = 0;
        MKDP(nd_nalg,mp0,nm);
        MKDAlg(nm,ONE,cd);
        if ( is_lc == 1 ) {
            /* if the lc is a rational number, we have nothing to do */
            if ( !mp0->dl->td )
                return 1;

            get_eg(&eg0);
            invdalg(cd,&inv);
            get_eg(&eg1); add_eg(&eg_invdalg,&eg0,&eg1);
            /* check the validity of inv */
            if ( mod && !rem(NM(inv->dn),mod) )
                return 0;
            CA(ma) = nf->one;
            is_lc = 0;
            ln = ONEN;
        } else {
            muldalg(cd,inv,&CA(ma));    
            lcmn(ln,NM(CA(ma)->dn),&ln);
        }
        if ( m ) {
            NEXT(ma) = mb; ma = mb;
        } else {
            NEXT(ma) = 0;
            break;
        }
    }
    /* l = lcm(denoms) */
    NTOQ(ln,1,l);
    for ( mr0 = 0, m = ma0; m; m = NEXT(m) ) {
        divq(l,CA(m)->dn,&mul);
        for ( mp = BDY(CA(m)->nm); mp; mp = NEXT(mp) ) {
            NEXTNM(mr0,mr);
            mulq((Q)mp->c,mul,&CQ(mr));
            dl = mp->dl;
            td = TD(DL(m));
            ndl_copy(DL(m),DL(mr));
            for ( i = 0; i < nd_nalg; i++ ) {
                e = dl->d[i];
                PUT_EXP(DL(mr),i+nd_ntrans,e);
                td += MUL_WEIGHT(e,i+nd_ntrans);
            }
            if ( nd_module ) MPOS(DL(mr)) = MPOS(DL(m));
            TD(DL(mr)) = td;
            if ( nd_blockmask) ndl_weight_mask(DL(mr));
        }
    }
    NEXT(mr) = 0;
    for ( len = 0, mr = mr0; mr; mr = NEXT(mr), len++ );
    MKND(NV(*p),mr0,len,r);
    /* XXX */
    SG(r) = SG(*p);
    nd_free(*p);
    *p = r;
    return 1;
}

NODE reverse_node(NODE n)
{
    NODE t,t1;

    for ( t = 0; n; n = NEXT(n) ) {
        MKNODE(t1,BDY(n),t); t = t1;
    }
    return t;
}

P ndc_div(int mod,union oNDC a,union oNDC b)
{
    union oNDC c;
    int inv,t;

    if ( mod == -1 ) c.m = _mulsf(a.m,_invsf(b.m));
    else if ( mod ) {
        inv = invm(b.m,mod);
        DMAR(a.m,inv,0,mod,t); c.m = t;
    } else if ( nd_vc )
       divsp(nd_vc,a.p,b.p,&c.p);
    else
       divq(a.z,b.z,&c.z);
    return ndctop(mod,c);
}

P ndctop(int mod,union oNDC c)
{
    Q q;
    int e;
    GFS gfs;

    if ( mod == -1 ) {
        e = IFTOF(c.m); MKGFS(e,gfs); return (P)gfs;
    } else if ( mod ) {
        STOQ(c.m,q); return (P)q;
    } else
        return (P)c.p;
}

/* [0,0,0,cont] = p -> p/cont */

void finalize_tracelist(int i,P cont)
{
	 LIST l;
	 NODE node;
     Q iq;

	 if ( !UNIQ(cont) ) {
         node = mknode(4,0,0,0,cont);
         MKLIST(l,node); MKNODE(node,l,nd_tracelist);
		 nd_tracelist = node;
	 }
     STOQ(i,iq);
     nd_tracelist = reverse_node(nd_tracelist);
     MKLIST(l,nd_tracelist);
     node = mknode(2,iq,l); MKLIST(l,node);
     MKNODE(node,l,nd_alltracelist); MKLIST(l,node);
     nd_alltracelist = node; nd_tracelist = 0;
}

void conv_ilist(int demand,int trace,NODE g,int **indp)
{
    int n,i,j;
	int *ind;
	NODE t;

    n = length(g);
	ind = (int *)MALLOC(n*sizeof(int));
	for ( i = 0, t = g; i < n; i++, t = NEXT(t) ) {
		j = (long)BDY(t); ind[i] = j;
		BDY(t) = (pointer)(demand?ndv_load(j):(trace?nd_ps_trace[j]:nd_ps[j]));
	}
	if ( indp ) *indp = ind;
}