===================================================================
RCS file: /home/cvs/OpenXM/src/kan96xx/Kan/gb.c,v
retrieving revision 1.6
retrieving revision 1.10
diff -u -p -r1.6 -r1.10
--- OpenXM/src/kan96xx/Kan/gb.c	2002/02/10 08:22:56	1.6
+++ OpenXM/src/kan96xx/Kan/gb.c	2005/06/16 06:54:55	1.10
@@ -1,4 +1,4 @@
-/* $OpenXM: OpenXM/src/kan96xx/Kan/gb.c,v 1.5 2001/05/04 01:06:23 takayama Exp $ */
+/* $OpenXM: OpenXM/src/kan96xx/Kan/gb.c,v 1.9 2005/06/09 04:09:22 takayama Exp $ */
 /*  untabify on May 4, 2001 */
 #include <stdio.h>
 #include "datatype.h"
@@ -23,6 +23,8 @@ extern int UseCriterion2B;
 extern int Spairs;
 extern int Criterion2B, Criterion2F, Criterion2M;
 extern int AutoReduce;
+extern int TraceLift;
+extern struct ring *TraceLift_ringmod;
 static int MaxLength[DMAX];
 static int SpNumber[DMAX];
 
@@ -160,13 +162,15 @@ struct gradedPairs *updatePairs(grD,gt,gtGrade,t,grG)
   return(grD);
 }
 
-struct gradedPolySet *groebner_gen(f,needBack,needSyz,grP,countDown,forceReduction)
+struct gradedPolySet *groebner_gen(f,needBack,needSyz,grP,countDown,forceReduction,reduceOnly,gbCheck)
      struct arrayOfPOLY *f;
      int needBack;
      int needSyz;
      struct pair **grP;  /* if (needSyz), it is set. */
      int countDown;
      int forceReduction;
+     int reduceOnly;
+     int gbCheck;
 {
   int r;
   struct gradedPolySet *g;
@@ -192,8 +196,10 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
   extern struct ring *CurrentRingp;
   extern char *F_mpMult;
   struct ring *rp;
+  int first;
   int statisticsPL, statisticsCount;
 
+
   if (Statistics) {
     for (i=0; i<DMAX; i++) MaxLength[i] = SpNumber[i] = 0;
   }
@@ -210,15 +216,21 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
 
   Spairs = Criterion1 = Criterion2B = Criterion2F = Criterion2M = 0;
   
-  g = newGradedPolySet(INITGRADE);
+  g = newGradedPolySet(INITGRADE); g->gb = 1;
   d = newGradedPairs(INITGRADE*2);
   for (i=0; i<g->lim; i++) {
     g->polys[i] = newPolySet(INITSIZE);
   }
 
+  first = 1;
   for (i=0; i<r; i++) {
     gt = getArrayOfPOLY(f,i);
     if (gt ISZERO) { rp = CurrentRingp; } else { rp = gt->m->ringp; }
+	if (TraceLift && (!(gt ISZERO)) && first) {
+	  TraceLift_ringmod = newRingOverFp(rp,getPrime(TraceLift)); first = 0;
+	  if (KanGBmessage) printf("Prime number for the trace lift is %d.\n",
+							   TraceLift_ringmod->p);
+	}
     grade = -1; whereInG(g,gt,&grade,&indx,Sugar);
     if (KanGBmessage == 2) {
       printf("init=%s, ",POLYToString(head(gt),'*',1));
@@ -236,7 +248,8 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
       g = putPolyInG(g,gt,grade,indx,syzp,1,serial);
     }
 
-    markRedundant0(g,grade,indx);
+    /* markRedundant0(g,grade,indx); ?*/
+	markGeneratorInG(g,grade,indx);  /*?*/
     if (Debug) {
       outputGradedPairs(d); outputGradedPolySet(g,needSyz);
     }
@@ -249,11 +262,18 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
   while ((top = getPair(d)) != (struct pair *)NULL) {
     ig = top->ig; ii = top->ii; /* [ig,ii] */
     jg = top->jg; ji = top->ji; /* [jg,ji] */
+	/*
+    if (g->polys[ig]->del[ii] || g->polys[jg]->del[ji]) {
+      if (KanGBmessage) printf("p");
+      continue; 
+    }  Don't do this.
+	*/
     gi = g->polys[ig]->g[ii];
     gj = g->polys[jg]->g[ji];
 
     Spairs++;
-    h = (*sp)(gi,gj);
+	if (reduceOnly && (!needSyz) && (!needBack)) h = spZero(); /* rd = 0 */
+	else h = (*sp)(gi,gj);
     rd = ppAddv(ppMult(h.a,gi),ppMult(h.b,gj));
 
     if (Statistics) {
@@ -298,6 +318,15 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
     }
 
     if (!(rd ISZERO)) {
+      if (gbCheck) {
+		/* Abort the calculation. */
+		g->gb = 0;
+		if (KanGBmessage) {
+		  printf("gbCheck failed. \n");
+		  printf("Note that the result is NOT groebner basis.\n");
+		}
+		break;
+      }
       if (needBack || needSyz) {
         syzp = newSyz0();
         syzp->cf = syzCf; /* no meaning */
@@ -337,6 +366,7 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
           if (countDown == 0) {
             printf("\nThe computation of the Groebner basis is suspended because of countDown==0.\n");
             printf("Note that the result is NOT groebner basis.\n");
+            g->gb = 0;
             break;
           }
         }
@@ -358,6 +388,7 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
         printf("Computation of the Groebner basis is suspended bacause of StopDegree < computing grade.\n");
         printf("Note that the result is NOT groebner basis.\n");
       }
+      g->gb = 0;
       break;
     }
   }
@@ -393,7 +424,7 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
     printf("\n");
   }
 
-  if (AutoReduce) {
+  if (AutoReduce || reduceOnly) {
     toReducedBasis(g,needBack,needSyz);
   }
   
@@ -490,6 +521,7 @@ void toReducedBasis(struct gradedPolySet *grP,int need
   if (KanGBmessage) {
     printf("Done(reduced basis)\n");
   }
+  grP->reduced = 1;
 }