===================================================================
RCS file: /home/cvs/OpenXM/src/kan96xx/Kan/gb.c,v
retrieving revision 1.7
retrieving revision 1.14
diff -u -p -r1.7 -r1.14
--- OpenXM/src/kan96xx/Kan/gb.c	2003/07/30 09:00:52	1.7
+++ OpenXM/src/kan96xx/Kan/gb.c	2020/10/06 11:33:46	1.14
@@ -1,6 +1,7 @@
-/* $OpenXM: OpenXM/src/kan96xx/Kan/gb.c,v 1.6 2002/02/10 08:22:56 takayama Exp $ */
+/* $OpenXM: OpenXM/src/kan96xx/Kan/gb.c,v 1.13 2005/07/07 02:59:47 takayama Exp $ */
 /*  untabify on May 4, 2001 */
 #include <stdio.h>
+#include <string.h>
 #include "datatype.h"
 #include "extern2.h"
 #include "matrix.h"
@@ -23,6 +24,8 @@ 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 +163,15 @@ 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;
@@ -191,9 +196,15 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
   extern int StopDegree;
   extern struct ring *CurrentRingp;
   extern char *F_mpMult;
+  extern int Homogenize;
   struct ring *rp;
+  int first;
   int statisticsPL, statisticsCount;
 
+  if (KanGBmessage) {
+	printf("Homogenize=%d, countDown=%d, forceReduction=%d, reduceOnly=%d, gbCheck=%d\n",
+		   Homogenize,countDown, forceReduction, reduceOnly, gbCheck); 
+  }
   if (Statistics) {
     for (i=0; i<DMAX; i++) MaxLength[i] = SpNumber[i] = 0;
   }
@@ -210,15 +221,22 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
 
   Spairs = Criterion1 = Criterion2B = Criterion2F = Criterion2M = 0;
   
-  g = newGradedPolySet(INITGRADE);
+  g = newGradedPolySet(INITGRADE); g->gb = 1;
+  if (reduceOnly) g->gb = 2; /* unknown */
   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));
@@ -260,7 +278,8 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
     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) {
@@ -305,6 +324,15 @@ 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 */
@@ -344,6 +372,7 @@ 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;
           }
         }
@@ -365,6 +394,7 @@ 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;
     }
   }
@@ -400,7 +430,7 @@ struct gradedPolySet *groebner_gen(f,needBack,needSyz,
     printf("\n");
   }
 
-  if (AutoReduce) {
+  if (AutoReduce || reduceOnly) {
     toReducedBasis(g,needBack,needSyz);
   }
   
@@ -497,6 +527,7 @@ void toReducedBasis(struct gradedPolySet *grP,int need
   if (KanGBmessage) {
     printf("Done(reduced basis)\n");
   }
+  grP->reduced = 1;
 }