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Annotation of OpenXM_contrib2/asir2000/lib/bfct, Revision 1.20

1.2       noro        1: /*
                      2:  * Copyright (c) 1994-2000 FUJITSU LABORATORIES LIMITED
                      3:  * All rights reserved.
                      4:  *
                      5:  * FUJITSU LABORATORIES LIMITED ("FLL") hereby grants you a limited,
                      6:  * non-exclusive and royalty-free license to use, copy, modify and
                      7:  * redistribute, solely for non-commercial and non-profit purposes, the
                      8:  * computer program, "Risa/Asir" ("SOFTWARE"), subject to the terms and
                      9:  * conditions of this Agreement. For the avoidance of doubt, you acquire
                     10:  * only a limited right to use the SOFTWARE hereunder, and FLL or any
                     11:  * third party developer retains all rights, including but not limited to
                     12:  * copyrights, in and to the SOFTWARE.
                     13:  *
                     14:  * (1) FLL does not grant you a license in any way for commercial
                     15:  * purposes. You may use the SOFTWARE only for non-commercial and
                     16:  * non-profit purposes only, such as academic, research and internal
                     17:  * business use.
                     18:  * (2) The SOFTWARE is protected by the Copyright Law of Japan and
                     19:  * international copyright treaties. If you make copies of the SOFTWARE,
                     20:  * with or without modification, as permitted hereunder, you shall affix
                     21:  * to all such copies of the SOFTWARE the above copyright notice.
                     22:  * (3) An explicit reference to this SOFTWARE and its copyright owner
                     23:  * shall be made on your publication or presentation in any form of the
                     24:  * results obtained by use of the SOFTWARE.
                     25:  * (4) In the event that you modify the SOFTWARE, you shall notify FLL by
1.3       noro       26:  * e-mail at risa-admin@sec.flab.fujitsu.co.jp of the detailed specification
1.2       noro       27:  * for such modification or the source code of the modified part of the
                     28:  * SOFTWARE.
                     29:  *
                     30:  * THE SOFTWARE IS PROVIDED AS IS WITHOUT ANY WARRANTY OF ANY KIND. FLL
                     31:  * MAKES ABSOLUTELY NO WARRANTIES, EXPRESSED, IMPLIED OR STATUTORY, AND
                     32:  * EXPRESSLY DISCLAIMS ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS
                     33:  * FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT OF THIRD PARTIES'
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                     35:  * MODIFICATIONS, EXTENSIONS, OR ADDITIONS TO THIS WARRANTY.
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                     38:  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, PUNITIVE OR CONSEQUENTIAL
                     39:  * DAMAGES OF ANY CHARACTER, INCLUDING, WITHOUT LIMITATION, DAMAGES
                     40:  * ARISING OUT OF OR RELATING TO THE SOFTWARE OR THIS AGREEMENT, DAMAGES
                     41:  * FOR LOSS OF GOODWILL, WORK STOPPAGE, OR LOSS OF DATA, OR FOR ANY
                     42:  * DAMAGES, EVEN IF FLL SHALL HAVE BEEN INFORMED OF THE POSSIBILITY OF
                     43:  * SUCH DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY. EVEN IF A PART
                     44:  * OF THE SOFTWARE HAS BEEN DEVELOPED BY A THIRD PARTY, THE THIRD PARTY
                     45:  * DEVELOPER SHALL HAVE NO LIABILITY IN CONNECTION WITH THE USE,
                     46:  * PERFORMANCE OR NON-PERFORMANCE OF THE SOFTWARE.
                     47:  *
1.20    ! noro       48:  * $OpenXM: OpenXM_contrib2/asir2000/lib/bfct,v 1.19 2002/01/29 02:03:41 noro Exp $
1.10      noro       49:  */
1.1       noro       50: /* requires 'primdec' */
                     51:
1.6       noro       52: /* annihilating ideal of F^s */
1.1       noro       53:
                     54: def ann(F)
                     55: {
                     56:        V = vars(F);
                     57:        N = length(V);
1.8       noro       58:        D = newvect(N);
                     59:
                     60:        for ( I = 0; I < N; I++ )
                     61:                D[I] = [deg(F,V[I]),V[I]];
                     62:        qsort(D,compare_first);
                     63:        for ( V = [], I = N-1; I >= 0; I-- )
                     64:                V = cons(D[I][1],V);
                     65:
1.1       noro       66:        for ( I = N-1, DV = []; I >= 0; I-- )
                     67:                DV = cons(strtov("d"+rtostr(V[I])),DV);
1.8       noro       68:
                     69:        W = append([y1,y2,t],V);
1.1       noro       70:        DW = append([dy1,dy2,dt],DV);
1.8       noro       71:
                     72:        B = [1-y1*y2,t-y1*F];
1.1       noro       73:        for ( I = 0; I < N; I++ ) {
                     74:                B = cons(DV[I]+y1*diff(F,V[I])*dt,B);
                     75:        }
1.10      noro       76:
                     77:        /* homogenized (heuristics) */
1.1       noro       78:        dp_nelim(2);
1.10      noro       79:        G0 = dp_weyl_gr_main(B,append(W,DW),1,0,6);
1.1       noro       80:        G1 = [];
                     81:        for ( T = G0; T != []; T = cdr(T) ) {
                     82:                E = car(T); VL = vars(E);
                     83:                if ( !member(y1,VL) && !member(y2,VL) )
                     84:                        G1 = cons(E,G1);
                     85:        }
1.12      noro       86:        G2 = map(psi,G1,t,dt);
                     87:        G3 = map(subst,G2,t,-1-s);
                     88:        return G3;
1.1       noro       89: }
                     90:
1.10      noro       91: /*
                     92:  * compute J_f|s=r, where r = the minimal integral root of global b_f(s)
                     93:  * ann0(F) returns [MinRoot,Ideal]
                     94:  */
                     95:
                     96: def ann0(F)
                     97: {
                     98:        V = vars(F);
                     99:        N = length(V);
                    100:        D = newvect(N);
                    101:
                    102:        for ( I = 0; I < N; I++ )
                    103:                D[I] = [deg(F,V[I]),V[I]];
                    104:        qsort(D,compare_first);
                    105:        for ( V = [], I = 0; I < N; I++ )
                    106:                V = cons(D[I][1],V);
                    107:
                    108:        for ( I = N-1, DV = []; I >= 0; I-- )
                    109:                DV = cons(strtov("d"+rtostr(V[I])),DV);
                    110:
                    111:        /* XXX : heuristics */
                    112:        W = append([y1,y2,t],reverse(V));
                    113:        DW = append([dy1,dy2,dt],reverse(DV));
                    114:        WDW = append(W,DW);
                    115:
                    116:        B = [1-y1*y2,t-y1*F];
                    117:        for ( I = 0; I < N; I++ ) {
                    118:                B = cons(DV[I]+y1*diff(F,V[I])*dt,B);
                    119:        }
                    120:
                    121:        /* homogenized (heuristics) */
                    122:        dp_nelim(2);
                    123:        G0 = dp_weyl_gr_main(B,WDW,1,0,6);
                    124:        G1 = [];
                    125:        for ( T = G0; T != []; T = cdr(T) ) {
                    126:                E = car(T); VL = vars(E);
                    127:                if ( !member(y1,VL) && !member(y2,VL) )
                    128:                        G1 = cons(E,G1);
                    129:        }
1.12      noro      130:        G2 = map(psi,G1,t,dt);
                    131:        G3 = map(subst,G2,t,-1-s);
1.10      noro      132:
1.12      noro      133:        /* G3 = J_f(s) */
1.10      noro      134:
                    135:        V1 = cons(s,V); DV1 = cons(ds,DV); V1DV1 = append(V1,DV1);
1.12      noro      136:        G4 = dp_weyl_gr_main(cons(F,G3),V1DV1,0,1,0);
                    137:        Bf = weyl_minipoly(G4,V1DV1,0,s);
1.10      noro      138:
                    139:        FList = cdr(fctr(Bf));
                    140:        for ( T = FList, Min = 0; T != []; T = cdr(T) ) {
                    141:                LF = car(car(T));
                    142:                Root = -coef(LF,0)/coef(LF,1);
                    143:                if ( dn(Root) == 1 && Root < Min )
                    144:                        Min = Root;
                    145:        }
1.12      noro      146:        return [Min,map(subst,G3,s,Min)];
1.10      noro      147: }
                    148:
1.7       noro      149: def indicial1(F,V)
1.6       noro      150: {
                    151:        W = append([y1,t],V);
                    152:        N = length(V);
                    153:        B = [t-y1*F];
                    154:        for ( I = N-1, DV = []; I >= 0; I-- )
                    155:                DV = cons(strtov("d"+rtostr(V[I])),DV);
                    156:        DW = append([dy1,dt],DV);
                    157:        for ( I = 0; I < N; I++ ) {
                    158:                B = cons(DV[I]+y1*diff(F,V[I])*dt,B);
                    159:        }
                    160:        dp_nelim(1);
1.10      noro      161:
                    162:        /* homogenized (heuristics) */
1.7       noro      163:        G0 = dp_weyl_gr_main(B,append(W,DW),1,0,6);
1.6       noro      164:        G1 = map(subst,G0,y1,1);
                    165:        G2 = map(psi,G1,t,dt);
                    166:        G3 = map(subst,G2,t,-s-1);
                    167:        return G3;
                    168: }
                    169:
                    170: def psi(F,T,DT)
                    171: {
                    172:        D = dp_ptod(F,[T,DT]);
                    173:        Wmax = weight(D);
                    174:        D1 = dp_rest(D);
                    175:        for ( ; D1; D1 = dp_rest(D1) )
                    176:                if ( weight(D1) > Wmax )
                    177:                        Wmax = weight(D1);
                    178:        for ( D1 = D, Dmax = 0; D1; D1 = dp_rest(D1) )
                    179:                if ( weight(D1) == Wmax )
                    180:                        Dmax += dp_hm(D1);
                    181:        if ( Wmax >= 0 )
                    182:                Dmax = dp_weyl_mul(<<Wmax,0>>,Dmax);
                    183:        else
                    184:                Dmax = dp_weyl_mul(<<0,-Wmax>>,Dmax);
                    185:        Rmax = dp_dtop(Dmax,[T,DT]);
                    186:        R = b_subst(subst(Rmax,DT,1),T);
                    187:        return R;
                    188: }
                    189:
                    190: def weight(D)
                    191: {
                    192:        V = dp_etov(D);
                    193:        return V[1]-V[0];
                    194: }
                    195:
                    196: def compare_first(A,B)
                    197: {
                    198:        A0 = car(A);
                    199:        B0 = car(B);
                    200:        if ( A0 > B0 )
                    201:                return 1;
                    202:        else if ( A0 < B0 )
                    203:                return -1;
                    204:        else
                    205:                return 0;
                    206: }
                    207:
1.13      noro      208: /* generic b-function w.r.t. weight vector W */
                    209:
                    210: def generic_bfct(F,V,DV,W)
                    211: {
                    212:        N = length(V);
                    213:        N2 = N*2;
                    214:
1.16      noro      215:        /* If W is a list, convert it to a vector */
                    216:        if ( type(W) == 4 )
                    217:                W = newvect(length(W),W);
1.15      noro      218:        dp_weyl_set_weight(W);
                    219:
1.14      noro      220:        /* create a term order M in D<x,d> (DRL) */
1.13      noro      221:        M = newmat(N2,N2);
                    222:        for ( J = 0; J < N2; J++ )
                    223:                M[0][J] = 1;
                    224:        for ( I = 1; I < N2; I++ )
                    225:                M[I][N2-I] = -1;
                    226:
                    227:        VDV = append(V,DV);
                    228:
                    229:        /* create a non-term order MW in D<x,d> */
                    230:        MW = newmat(N2+1,N2);
                    231:        for ( J = 0; J < N; J++ )
                    232:                MW[0][J] = -W[J];
                    233:        for ( ; J < N2; J++ )
                    234:                MW[0][J] = W[J-N];
                    235:        for ( I = 1; I <= N2; I++ )
                    236:                for ( J = 0; J < N2; J++ )
                    237:                        MW[I][J] = M[I-1][J];
                    238:
                    239:        /* create a homogenized term order MWH in D<x,d,h> */
                    240:        MWH = newmat(N2+2,N2+1);
                    241:        for ( J = 0; J <= N2; J++ )
                    242:                MWH[0][J] = 1;
                    243:        for ( I = 1; I <= N2+1; I++ )
                    244:                for ( J = 0; J < N2; J++ )
                    245:                        MWH[I][J] = MW[I-1][J];
                    246:
                    247:        /* homogenize F */
                    248:        VDVH = append(VDV,[h]);
                    249:        FH = map(dp_dtop,map(dp_homo,map(dp_ptod,F,VDV)),VDVH);
                    250:
                    251:        /* compute a groebner basis of FH w.r.t. MWH */
1.20    ! noro      252:        dp_gr_flags(["Top",1]);
1.15      noro      253:        GH = dp_weyl_gr_main(FH,VDVH,0,1,11);
1.20    ! noro      254:        dp_gr_flags(["Top",0]);
1.13      noro      255:
                    256:        /* dehomigenize GH */
                    257:        G = map(subst,GH,h,1);
                    258:
                    259:        /* G is a groebner basis w.r.t. a non term order MW */
                    260:        /* take the initial part w.r.t. (-W,W) */
                    261:        GIN = map(initial_part,G,VDV,MW,W);
                    262:
                    263:        /* GIN is a groebner basis w.r.t. a term order M */
                    264:        /* As -W+W=0, gr_(-W,W)(D<x,d>) = D<x,d> */
                    265:
                    266:        /* find b(W1*x1*d1+...+WN*xN*dN) in Id(GIN) */
                    267:        for ( I = 0, T = 0; I < N; I++ )
                    268:                T += W[I]*V[I]*DV[I];
1.14      noro      269:        B = weyl_minipoly(GIN,VDV,0,T); /* M represents DRL order */
1.13      noro      270:        return B;
                    271: }
                    272:
1.18      noro      273: /* all term reduction + interreduce */
                    274: def generic_bfct_1(F,V,DV,W)
                    275: {
                    276:        N = length(V);
                    277:        N2 = N*2;
                    278:
                    279:        /* If W is a list, convert it to a vector */
                    280:        if ( type(W) == 4 )
                    281:                W = newvect(length(W),W);
                    282:        dp_weyl_set_weight(W);
                    283:
                    284:        /* create a term order M in D<x,d> (DRL) */
                    285:        M = newmat(N2,N2);
                    286:        for ( J = 0; J < N2; J++ )
                    287:                M[0][J] = 1;
                    288:        for ( I = 1; I < N2; I++ )
                    289:                M[I][N2-I] = -1;
                    290:
                    291:        VDV = append(V,DV);
                    292:
                    293:        /* create a non-term order MW in D<x,d> */
                    294:        MW = newmat(N2+1,N2);
                    295:        for ( J = 0; J < N; J++ )
                    296:                MW[0][J] = -W[J];
                    297:        for ( ; J < N2; J++ )
                    298:                MW[0][J] = W[J-N];
                    299:        for ( I = 1; I <= N2; I++ )
                    300:                for ( J = 0; J < N2; J++ )
                    301:                        MW[I][J] = M[I-1][J];
                    302:
                    303:        /* create a homogenized term order MWH in D<x,d,h> */
                    304:        MWH = newmat(N2+2,N2+1);
                    305:        for ( J = 0; J <= N2; J++ )
                    306:                MWH[0][J] = 1;
                    307:        for ( I = 1; I <= N2+1; I++ )
                    308:                for ( J = 0; J < N2; J++ )
                    309:                        MWH[I][J] = MW[I-1][J];
                    310:
                    311:        /* homogenize F */
                    312:        VDVH = append(VDV,[h]);
                    313:        FH = map(dp_dtop,map(dp_homo,map(dp_ptod,F,VDV)),VDVH);
                    314:
                    315:        /* compute a groebner basis of FH w.r.t. MWH */
                    316: /*     dp_gr_flags(["Top",1,"NoRA",1]); */
                    317:        GH = dp_weyl_gr_main(FH,VDVH,0,1,11);
                    318: /*     dp_gr_flags(["Top",0,"NoRA",0]); */
                    319:
                    320:        /* dehomigenize GH */
                    321:        G = map(subst,GH,h,1);
                    322:
                    323:        /* G is a groebner basis w.r.t. a non term order MW */
                    324:        /* take the initial part w.r.t. (-W,W) */
                    325:        GIN = map(initial_part,G,VDV,MW,W);
                    326:
                    327:        /* GIN is a groebner basis w.r.t. a term order M */
                    328:        /* As -W+W=0, gr_(-W,W)(D<x,d>) = D<x,d> */
                    329:
                    330:        /* find b(W1*x1*d1+...+WN*xN*dN) in Id(GIN) */
                    331:        for ( I = 0, T = 0; I < N; I++ )
                    332:                T += W[I]*V[I]*DV[I];
                    333:        B = weyl_minipoly(GIN,VDV,0,T); /* M represents DRL order */
                    334:        return B;
                    335: }
                    336:
1.13      noro      337: def initial_part(F,V,MW,W)
                    338: {
                    339:        N2 = length(V);
                    340:        N = N2/2;
                    341:        dp_ord(MW);
                    342:        DF = dp_ptod(F,V);
                    343:        R = dp_hm(DF);
                    344:        DF = dp_rest(DF);
                    345:
                    346:        E = dp_etov(R);
                    347:        for ( I = 0, TW = 0; I < N; I++ )
                    348:                TW += W[I]*(-E[I]+E[N+I]);
                    349:        RW = TW;
                    350:
                    351:        for ( ; DF; DF = dp_rest(DF) ) {
                    352:                E = dp_etov(DF);
                    353:                for ( I = 0, TW = 0; I < N; I++ )
                    354:                        TW += W[I]*(-E[I]+E[N+I]);
                    355:                if ( TW == RW )
                    356:                        R += dp_hm(DF);
                    357:                else if ( TW < RW )
                    358:                        break;
                    359:                else
                    360:                        error("initial_part : cannot happen");
                    361:        }
                    362:        return dp_dtop(R,V);
                    363:
                    364: }
                    365:
1.1       noro      366: /* b-function of F ? */
                    367:
                    368: def bfct(F)
                    369: {
                    370:        V = vars(F);
                    371:        N = length(V);
1.6       noro      372:        D = newvect(N);
1.7       noro      373:
1.6       noro      374:        for ( I = 0; I < N; I++ )
                    375:                D[I] = [deg(F,V[I]),V[I]];
                    376:        qsort(D,compare_first);
                    377:        for ( V = [], I = 0; I < N; I++ )
                    378:                V = cons(D[I][1],V);
1.1       noro      379:        for ( I = N-1, DV = []; I >= 0; I-- )
                    380:                DV = cons(strtov("d"+rtostr(V[I])),DV);
1.6       noro      381:        V1 = cons(s,V); DV1 = cons(ds,DV);
1.7       noro      382:
                    383:        G0 = indicial1(F,reverse(V));
                    384:        G1 = dp_weyl_gr_main(G0,append(V1,DV1),0,1,0);
                    385:        Minipoly = weyl_minipoly(G1,append(V1,DV1),0,s);
1.6       noro      386:        return Minipoly;
                    387: }
                    388:
1.14      noro      389: /* b-function computation via generic_bfct() (experimental) */
                    390:
                    391: def bfct_via_gbfct(F)
                    392: {
                    393:        V = vars(F);
                    394:        N = length(V);
                    395:        D = newvect(N);
                    396:
                    397:        for ( I = 0; I < N; I++ )
                    398:                D[I] = [deg(F,V[I]),V[I]];
                    399:        qsort(D,compare_first);
                    400:        for ( V = [], I = 0; I < N; I++ )
                    401:                V = cons(D[I][1],V);
                    402:        V = reverse(V);
                    403:        for ( I = N-1, DV = []; I >= 0; I-- )
                    404:                DV = cons(strtov("d"+rtostr(V[I])),DV);
                    405:
                    406:        B = [t-F];
                    407:        for ( I = 0; I < N; I++ ) {
                    408:                B = cons(DV[I]+diff(F,V[I])*dt,B);
                    409:        }
                    410:        V1 = cons(t,V); DV1 = cons(dt,DV);
                    411:        W = newvect(N+1);
                    412:        W[0] = 1;
1.18      noro      413:        R = generic_bfct_1(B,V1,DV1,W);
1.14      noro      414:
                    415:        return subst(R,s,-s-1);
                    416: }
                    417:
1.17      noro      418: /* use an order s.t. [t,x,y,z,...,dt,dx,dy,dz,...,h] */
                    419:
                    420: def bfct_via_gbfct_weight(F,V)
                    421: {
                    422:        N = length(V);
                    423:        D = newvect(N);
                    424:        Wt = getopt(weight);
1.18      noro      425:        if ( type(Wt) != 4 ) {
                    426:                for ( I = 0, Wt = []; I < N; I++ )
                    427:                        Wt = cons(1,Wt);
                    428:        }
                    429:        Tdeg = w_tdeg(F,V,Wt);
                    430:        WtV = newvect(2*(N+1)+1);
                    431:        WtV[0] = Tdeg;
                    432:        WtV[N+1] = 1;
                    433:        /* wdeg(V[I])=Wt[I], wdeg(DV[I])=Tdeg-Wt[I]+1 */
                    434:        for ( I = 1; I <= N; I++ ) {
                    435:                WtV[I] = Wt[I-1];
                    436:                WtV[N+1+I] = Tdeg-Wt[I-1]+1;
1.17      noro      437:        }
1.18      noro      438:        WtV[2*(N+1)] = 1;
                    439:        dp_set_weight(WtV);
1.17      noro      440:        for ( I = N-1, DV = []; I >= 0; I-- )
                    441:                DV = cons(strtov("d"+rtostr(V[I])),DV);
                    442:
                    443:        B = [t-F];
                    444:        for ( I = 0; I < N; I++ ) {
                    445:                B = cons(DV[I]+diff(F,V[I])*dt,B);
                    446:        }
                    447:        V1 = cons(t,V); DV1 = cons(dt,DV);
                    448:        W = newvect(N+1);
                    449:        W[0] = 1;
1.18      noro      450:        R = generic_bfct_1(B,V1,DV1,W);
                    451:        dp_set_weight(0);
1.17      noro      452:        return subst(R,s,-s-1);
                    453: }
                    454:
                    455: /* use an order s.t. [x,y,z,...,t,dx,dy,dz,...,dt,h] */
                    456:
                    457: def bfct_via_gbfct_weight_1(F,V)
                    458: {
                    459:        N = length(V);
                    460:        D = newvect(N);
                    461:        Wt = getopt(weight);
1.18      noro      462:        if ( type(Wt) != 4 ) {
                    463:                for ( I = 0, Wt = []; I < N; I++ )
                    464:                        Wt = cons(1,Wt);
                    465:        }
                    466:        Tdeg = w_tdeg(F,V,Wt);
                    467:        WtV = newvect(2*(N+1)+1);
                    468:        /* wdeg(V[I])=Wt[I], wdeg(DV[I])=Tdeg-Wt[I]+1 */
                    469:        for ( I = 0; I < N; I++ ) {
                    470:                WtV[I] = Wt[I];
                    471:                WtV[N+1+I] = Tdeg-Wt[I]+1;
1.17      noro      472:        }
1.18      noro      473:        WtV[N] = Tdeg;
                    474:        WtV[2*N+1] = 1;
                    475:        WtV[2*(N+1)] = 1;
                    476:        dp_set_weight(WtV);
1.17      noro      477:        for ( I = N-1, DV = []; I >= 0; I-- )
                    478:                DV = cons(strtov("d"+rtostr(V[I])),DV);
                    479:
                    480:        B = [t-F];
                    481:        for ( I = 0; I < N; I++ ) {
                    482:                B = cons(DV[I]+diff(F,V[I])*dt,B);
                    483:        }
                    484:        V1 = append(V,[t]); DV1 = append(DV,[dt]);
                    485:        W = newvect(N+1);
                    486:        W[N] = 1;
                    487:        R = generic_bfct(B,V1,DV1,W);
1.19      noro      488:        dp_set_weight(0);
                    489:        return subst(R,s,-s-1);
                    490: }
                    491:
                    492: def bfct_via_gbfct_weight_2(F,V)
                    493: {
                    494:        N = length(V);
                    495:        D = newvect(N);
                    496:        Wt = getopt(weight);
                    497:        if ( type(Wt) != 4 ) {
                    498:                for ( I = 0, Wt = []; I < N; I++ )
                    499:                        Wt = cons(1,Wt);
                    500:        }
                    501:        Tdeg = w_tdeg(F,V,Wt);
                    502:
                    503:        /* a weight for the first GB computation */
                    504:        /* [t,x1,...,xn,dt,dx1,...,dxn,h] */
                    505:        WtV = newvect(2*(N+1)+1);
                    506:        WtV[0] = Tdeg;
                    507:        WtV[N+1] = 1;
                    508:        WtV[2*(N+1)] = 1;
                    509:        /* wdeg(V[I])=Wt[I], wdeg(DV[I])=Tdeg-Wt[I]+1 */
                    510:        for ( I = 1; I <= N; I++ ) {
                    511:                WtV[I] = Wt[I-1];
                    512:                WtV[N+1+I] = Tdeg-Wt[I-1]+1;
                    513:        }
                    514:        dp_set_weight(WtV);
                    515:
                    516:        /* a weight for the second GB computation */
                    517:        /* [x1,...,xn,t,dx1,...,dxn,dt,h] */
                    518:        WtV2 = newvect(2*(N+1)+1);
                    519:        WtV2[N] = Tdeg;
                    520:        WtV2[2*N+1] = 1;
                    521:        WtV2[2*(N+1)] = 1;
                    522:        for ( I = 0; I < N; I++ ) {
                    523:                WtV2[I] = Wt[I];
                    524:                WtV2[N+1+I] = Tdeg-Wt[I]+1;
                    525:        }
                    526:
                    527:        for ( I = N-1, DV = []; I >= 0; I-- )
                    528:                DV = cons(strtov("d"+rtostr(V[I])),DV);
                    529:
                    530:        B = [t-F];
                    531:        for ( I = 0; I < N; I++ ) {
                    532:                B = cons(DV[I]+diff(F,V[I])*dt,B);
                    533:        }
                    534:        V1 = cons(t,V); DV1 = cons(dt,DV);
                    535:        V2 = append(V,[t]); DV2 = append(DV,[dt]);
                    536:        W = newvect(N+1,[1]);
                    537:        dp_weyl_set_weight(W);
                    538:
                    539:        VDV = append(V1,DV1);
                    540:        N1 = length(V1);
                    541:        N2 = N1*2;
                    542:
                    543:        /* create a non-term order MW in D<x,d> */
                    544:        MW = newmat(N2+1,N2);
                    545:        for ( J = 0; J < N1; J++ ) {
                    546:                MW[0][J] = -W[J]; MW[0][N1+J] = W[J];
                    547:        }
                    548:        for ( J = 0; J < N2; J++ ) MW[1][J] = 1;
                    549:        for ( I = 2; I <= N2; I++ ) MW[I][N2-I+1] = -1;
                    550:
                    551:        /* homogenize F */
                    552:        VDVH = append(VDV,[h]);
                    553:        FH = map(dp_dtop,map(dp_homo,map(dp_ptod,B,VDV)),VDVH);
                    554:
                    555:        /* compute a groebner basis of FH w.r.t. MWH */
                    556:        GH = dp_weyl_gr_main(FH,VDVH,0,1,11);
                    557:
                    558:        /* dehomigenize GH */
                    559:        G = map(subst,GH,h,1);
                    560:
                    561:        /* G is a groebner basis w.r.t. a non term order MW */
                    562:        /* take the initial part w.r.t. (-W,W) */
                    563:        GIN = map(initial_part,G,VDV,MW,W);
                    564:
                    565:        /* GIN is a groebner basis w.r.t. a term order M */
                    566:        /* As -W+W=0, gr_(-W,W)(D<x,d>) = D<x,d> */
                    567:
                    568:        /* find b(W1*x1*d1+...+WN*xN*dN) in Id(GIN) */
                    569:        for ( I = 0, T = 0; I < N1; I++ )
                    570:                T += W[I]*V1[I]*DV1[I];
                    571:
                    572:        /* change of ordering from VDV to VDV2 */
                    573:        VDV2 = append(V2,DV2);
                    574:        dp_set_weight(WtV2);
1.20    ! noro      575:        for ( Pind = 0; ; Pind++ ) {
        !           576:                Prime = lprime(Pind);
        !           577:                GIN2 = dp_weyl_gr_main(GIN,VDV2,0,-Prime,0);
        !           578:                if ( GIN2 ) break;
        !           579:        }
1.19      noro      580:
                    581:        R = weyl_minipoly(GIN2,VDV2,0,T); /* M represents DRL order */
1.18      noro      582:        dp_set_weight(0);
1.17      noro      583:        return subst(R,s,-s-1);
                    584: }
                    585:
1.6       noro      586: def weyl_minipolym(G,V,O,M,V0)
                    587: {
                    588:        N = length(V);
                    589:        Len = length(G);
                    590:        dp_ord(O);
                    591:        setmod(M);
                    592:        PS = newvect(Len);
                    593:        PS0 = newvect(Len);
                    594:
                    595:        for ( I = 0, T = G; T != []; T = cdr(T), I++ )
                    596:                PS0[I] = dp_ptod(car(T),V);
                    597:        for ( I = 0, T = G; T != []; T = cdr(T), I++ )
                    598:                PS[I] = dp_mod(dp_ptod(car(T),V),M,[]);
                    599:
                    600:        for ( I = Len - 1, GI = []; I >= 0; I-- )
                    601:                GI = cons(I,GI);
                    602:
                    603:        U = dp_mod(dp_ptod(V0,V),M,[]);
1.17      noro      604:        U = dp_weyl_nf_mod(GI,U,PS,1,M);
1.6       noro      605:
                    606:        T = dp_mod(<<0>>,M,[]);
                    607:        TT = dp_mod(dp_ptod(1,V),M,[]);
                    608:        G = H = [[TT,T]];
                    609:
                    610:        for ( I = 1; ; I++ ) {
1.14      noro      611:                if ( dp_gr_print() )
                    612:                        print(".",2);
1.6       noro      613:                T = dp_mod(<<I>>,M,[]);
                    614:
                    615:                TT = dp_weyl_nf_mod(GI,dp_weyl_mul_mod(TT,U,M),PS,1,M);
                    616:                H = cons([TT,T],H);
                    617:                L = dp_lnf_mod([TT,T],G,M);
1.14      noro      618:                if ( !L[0] ) {
                    619:                        if ( dp_gr_print() )
                    620:                                print("");
1.13      noro      621:                        return dp_dtop(L[1],[t]); /* XXX */
1.14      noro      622:                } else
1.6       noro      623:                        G = insert(G,L);
                    624:        }
                    625: }
                    626:
1.13      noro      627: def weyl_minipoly(G0,V0,O0,P)
1.6       noro      628: {
1.11      noro      629:        HM = hmlist(G0,V0,O0);
1.13      noro      630:
                    631:        N = length(V0);
                    632:        Len = length(G0);
                    633:        dp_ord(O0);
                    634:        PS = newvect(Len);
                    635:        for ( I = 0, T = G0, HL = []; T != []; T = cdr(T), I++ )
                    636:                PS[I] = dp_ptod(car(T),V0);
                    637:        for ( I = Len - 1, GI = []; I >= 0; I-- )
                    638:                GI = cons(I,GI);
1.20    ! noro      639:        PSM = newvect(Len);
1.13      noro      640:        DP = dp_ptod(P,V0);
                    641:
1.20    ! noro      642:        for ( Pind = 0; ; Pind++ ) {
        !           643:                Prime = lprime(Pind);
1.11      noro      644:                if ( !valid_modulus(HM,Prime) )
                    645:                        continue;
1.20    ! noro      646:                setmod(Prime);
        !           647:                for ( I = 0, T = G0, HL = []; T != []; T = cdr(T), I++ )
        !           648:                        PSM[I] = dp_mod(dp_ptod(car(T),V0),Prime,[]);
1.13      noro      649:
                    650:                NFP = weyl_nf(GI,DP,1,PS);
1.20    ! noro      651:                NFPM = dp_mod(NFP[0],Prime,[])/ptomp(NFP[1],Prime);
        !           652:
1.13      noro      653:                NF = [[dp_ptod(1,V0),1]];
                    654:                LCM = 1;
                    655:
1.20    ! noro      656:                TM = dp_mod(<<0>>,Prime,[]);
        !           657:                TTM = dp_mod(dp_ptod(1,V0),Prime,[]);
        !           658:                GM = NFM = [[TTM,TM]];
        !           659:
        !           660:                for ( D = 1; ; D++ ) {
1.14      noro      661:                        if ( dp_gr_print() )
                    662:                                print(".",2);
1.13      noro      663:                        NFPrev = car(NF);
                    664:                        NFJ = weyl_nf(GI,
                    665:                                dp_weyl_mul(NFP[0],NFPrev[0]),NFP[1]*NFPrev[1],PS);
                    666:                        NFJ = remove_cont(NFJ);
                    667:                        NF = cons(NFJ,NF);
                    668:                        LCM = ilcm(LCM,NFJ[1]);
1.20    ! noro      669:
        !           670:                        /* modular computation */
        !           671:                        TM = dp_mod(<<D>>,Prime,[]);
        !           672:                        TTM = dp_mod(NFJ[0],Prime,[])/ptomp(NFJ[1],Prime);
        !           673:                        NFM = cons([TTM,TM],NFM);
        !           674:                        LM = dp_lnf_mod([TTM,TM],GM,Prime);
        !           675:                        if ( !LM[0] )
        !           676:                                break;
        !           677:                        else
        !           678:                                GM = insert(GM,LM);
1.13      noro      679:                }
1.20    ! noro      680:
1.14      noro      681:                if ( dp_gr_print() )
                    682:                        print("");
1.13      noro      683:                U = NF[0][0]*idiv(LCM,NF[0][1]);
                    684:                Coef = [];
                    685:                for ( J = D-1; J >= 0; J-- ) {
                    686:                        Coef = cons(strtov("u"+rtostr(J)),Coef);
                    687:                        U += car(Coef)*NF[D-J][0]*idiv(LCM,NF[D-J][1]);
                    688:                }
1.6       noro      689:
1.13      noro      690:                for ( UU = U, Eq = []; UU; UU = dp_rest(UU) )
                    691:                        Eq = cons(dp_hc(UU),Eq);
                    692:                M = etom([Eq,Coef]);
                    693:                B = henleq(M,Prime);
                    694:                if ( dp_gr_print() )
                    695:                        print("");
1.6       noro      696:                if ( B ) {
1.13      noro      697:                        R = 0;
                    698:                        for ( I = 0; I < D; I++ )
                    699:                                R += B[0][I]*s^I;
                    700:                        R += B[1]*s^D;
1.6       noro      701:                        return R;
                    702:                }
                    703:        }
                    704: }
                    705:
                    706: def weyl_nf(B,G,M,PS)
                    707: {
                    708:        for ( D = 0; G; ) {
                    709:                for ( U = 0, L = B; L != []; L = cdr(L) ) {
                    710:                        if ( dp_redble(G,R=PS[car(L)]) > 0 ) {
                    711:                                GCD = igcd(dp_hc(G),dp_hc(R));
                    712:                                CG = idiv(dp_hc(R),GCD); CR = idiv(dp_hc(G),GCD);
                    713:                                U = CG*G-dp_weyl_mul(CR*dp_subd(G,R),R);
                    714:                                if ( !U )
                    715:                                        return [D,M];
                    716:                                D *= CG; M *= CG;
                    717:                                break;
                    718:                        }
                    719:                }
                    720:                if ( U )
                    721:                        G = U;
                    722:                else {
                    723:                        D += dp_hm(G); G = dp_rest(G);
                    724:                }
                    725:        }
                    726:        return [D,M];
                    727: }
                    728:
                    729: def weyl_nf_mod(B,G,PS,Mod)
                    730: {
                    731:        for ( D = 0; G; ) {
                    732:                for ( U = 0, L = B; L != []; L = cdr(L) ) {
                    733:                        if ( dp_redble(G,R=PS[car(L)]) > 0 ) {
                    734:                                CR = dp_hc(G)/dp_hc(R);
                    735:                                U = G-dp_weyl_mul_mod(CR*dp_mod(dp_subd(G,R),Mod,[]),R,Mod);
                    736:                                if ( !U )
                    737:                                        return D;
1.1       noro      738:                                break;
1.6       noro      739:                        }
                    740:                }
                    741:                if ( U )
                    742:                        G = U;
                    743:                else {
                    744:                        D += dp_hm(G); G = dp_rest(G);
1.1       noro      745:                }
                    746:        }
1.6       noro      747:        return D;
1.1       noro      748: }
                    749:
                    750: def remove_zero(L)
                    751: {
                    752:        for ( R = []; L != []; L = cdr(L) )
                    753:                if ( car(L) )
                    754:                        R = cons(car(L),R);
                    755:        return R;
                    756: }
                    757:
                    758: def z_subst(F,V)
                    759: {
                    760:        for ( ; V != []; V = cdr(V) )
                    761:                F = subst(F,car(V),0);
                    762:        return F;
                    763: }
                    764:
                    765: def flatmf(L) {
                    766:     for ( S = []; L != []; L = cdr(L) )
                    767:                if ( type(F=car(car(L))) != NUM )
                    768:                        S = append(S,[F]);
                    769:        return S;
                    770: }
                    771:
                    772: def member(A,L) {
                    773:     for ( ; L != []; L = cdr(L) )
                    774:                if ( A == car(L) )
                    775:                        return 1;
                    776:        return 0;
                    777: }
                    778:
                    779: def intersection(A,B)
                    780: {
                    781:        for ( L = []; A != []; A = cdr(A) )
                    782:        if ( member(car(A),B) )
                    783:                L = cons(car(A),L);
                    784:        return L;
                    785: }
                    786:
                    787: def b_subst(F,V)
                    788: {
                    789:        D = deg(F,V);
                    790:        C = newvect(D+1);
                    791:        for ( I = D; I >= 0; I-- )
                    792:                C[I] = coef(F,I,V);
                    793:        for ( I = 0, R = 0; I <= D; I++ )
                    794:                if ( C[I] )
                    795:                        R += C[I]*v_factorial(V,I);
                    796:        return R;
                    797: }
                    798:
                    799: def v_factorial(V,N)
                    800: {
                    801:        for ( J = N-1, R = 1; J >= 0; J-- )
                    802:                R *= V-J;
1.17      noro      803:        return R;
                    804: }
                    805:
                    806: def w_tdeg(F,V,W)
                    807: {
                    808:        dp_set_weight(newvect(length(W),W));
                    809:        T = dp_ptod(F,V);
                    810:        for ( R = 0; T; T = cdr(T) ) {
                    811:                D = dp_td(T);
                    812:                if ( D > R ) R = D;
                    813:        }
1.1       noro      814:        return R;
                    815: }
                    816: end$
                    817:

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