===================================================================
RCS file: /home/cvs/OpenXM_contrib2/asir2000/builtin/gf.c,v
retrieving revision 1.5
retrieving revision 1.10
diff -u -p -r1.5 -r1.10
--- OpenXM_contrib2/asir2000/builtin/gf.c	2001/05/09 01:41:41	1.5
+++ OpenXM_contrib2/asir2000/builtin/gf.c	2001/07/03 01:41:25	1.10
@@ -45,7 +45,7 @@
  * DEVELOPER SHALL HAVE NO LIABILITY IN CONNECTION WITH THE USE,
  * PERFORMANCE OR NON-PERFORMANCE OF THE SOFTWARE.
  *
- * $OpenXM: OpenXM_contrib2/asir2000/builtin/gf.c,v 1.4 2000/08/22 05:03:57 noro Exp $ 
+ * $OpenXM: OpenXM_contrib2/asir2000/builtin/gf.c,v 1.9 2001/06/28 08:57:20 noro Exp $ 
 */
 #include "ca.h"
 #include "parse.h"
@@ -74,6 +74,7 @@ void pwr_mod(P,P,V,P,int,N,P *);
 void rem_mod(P,P,V,P,int,P *);
 
 void Pnullspace(),Pgcda_mod(),Pftest(),Presfmain(),Ppwr_mod(),Puhensel();
+void Psfuhensel();
 
 void Pnullspace_ff();
 
@@ -83,6 +84,7 @@ void Plinear_form_to_vect(),Pvect_to_linear_form();
 void solve_linear_equation_gf2n(GF2N **,int,int,int *);
 void linear_form_to_array(P,VL,int,Num *);
 void array_to_linear_form(Num *,VL,int,P *);
+void sfuhensel(P,NODE,GFS,int,NODE *);
 
 extern int current_ff;
 
@@ -95,6 +97,7 @@ struct ftab gf_tab[] = {
 	{"resfmain",Presfmain,4},
 	{"pwr_mod",Ppwr_mod,6},
 	{"uhensel",Puhensel,4},
+	{"sfuhensel",Psfuhensel,4},
 	{0,0,0},
 };
 
@@ -175,6 +178,96 @@ NODE *rp;
 	for ( i = nf-1, top = 0; i >= 0; i-- ) {
 		lumtop(v,mod,bound,rlist->c[i],&s);
 		MKNODE(t,s,top); top = t;
+	}
+	*rp = top;
+}
+
+void Psfuhensel(arg,rp)
+NODE arg;
+LIST *rp;
+{
+	P f;
+	int bound;
+	NODE r,mfl;
+	GFS ev;
+
+	f = (P)ARG0(arg);
+	mfl = BDY((LIST)ARG1(arg));
+	ev = (GFS)ARG2(arg);
+	bound = QTOS((Q)ARG3(arg));
+	sfuhensel(f,mfl,ev,bound,&r);
+	MKLIST(*rp,r);
+}
+
+void sfuhensel(f,mfl,ev,bound,rp)
+P f;
+NODE mfl;
+GFS ev;
+int bound;
+NODE *rp;
+{
+	BM fl;
+	BM *r;
+	VL vl,nvl;
+	int i,fn,dx,dy;
+	NODE t,top;
+	UM fm,hm,q;
+	UM *gm;
+	V x,y;
+	P g,s,u;
+
+	clctv(CO,f,&vl);
+	if ( !vl || !vl->next || vl->next->next )
+		error("sfuhensel : f must be a bivariate poly");
+
+	for ( i = 0, t = mfl; t; i++, t = NEXT(t) );
+	fn = i;
+
+	gm = (UM *)MALLOC(fn*sizeof(UM));
+
+	/* XXX : more severe check is necessary */
+	x = VR((P)BDY(mfl));
+	y = vl->v == x ? vl->next->v : vl->v;
+
+	for ( i = 0, t = mfl; i < fn; i++, t = NEXT(t) ) {
+		gm[i] = (pointer)UMALLOC(getdeg(x,(P)BDY(t)));
+		ptosfum((P)BDY(t),gm[i]);
+	}
+
+	/* reorder f if necessary */
+	if ( vl->v != x ) {
+		reordvar(vl,x,&nvl); reorderp(nvl,vl,f,&g);
+		vl = nvl; f = g;
+	}
+	dx = getdeg(x,f);
+	dy = getdeg(y,f);
+	dy = MAX(dy,bound);
+	fl = BMALLOC(dx,dy);
+	ptosfbm(dy,f,fl);
+	shiftsfbm(fl,FTOIF(CONT(ev)));
+
+	/* fm = fl mod y */
+	fm = W_UMALLOC(dx);
+	cpyum(COEF(fl)[0],fm);
+	hm = W_UMALLOC(dx);
+
+	q = W_UMALLOC(dx);
+	r = (BM *)MLALLOC(fn*sizeof(BM));
+	for ( i = 0; i < fn-1; i++ ) {
+		/* fl = gm[i]*hm mod y */
+		divsfum(fm,gm[i],hm);
+		/* fl is replaced by the cofactor of gk mod y^bound */
+		/* r[i] = gk */
+		sfhenmain2(fl,gm[i],hm,bound,r+i);
+		cpyum(hm,fm);
+	}
+	/* finally, fl must be the lift of gm[fn-1] */
+	r[i] = fl;
+
+	for ( i = fn-1, top = 0; i >= 0; i-- ) {
+		sfbmtop(r[i],x,y,&s);
+		reorderp(CO,vl,s,&u);
+		MKNODE(t,u,top); top = t;
 	}
 	*rp = top;
 }