diff -ruN klic-3.003-2002-03-09b/include/klic/g_methtab.h klic-3.003-2002-03-11/include/klic/g_methtab.h
--- klic-3.003-2002-03-09b/include/klic/g_methtab.h	Sat Mar  9 14:02:05 2002
+++ klic-3.003-2002-03-11/include/klic/g_methtab.h	Mon Mar 11 13:21:48 2002
@@ -77,7 +77,7 @@
 };
 
 struct generator_object_method_table {
-  void (*active_unify)(/* q self, q other */);
+  int (*active_unify)(/* q self, q other */);
   q (*generate)(/* struct generator_object* self */);
   q (*suspend)(/* q reference, struct goalrec* goal */);
   long (*print)/* print what ? */ (/* struct generator_object* self,
diff -ruN klic-3.003-2002-03-09b/include/klic/gg_macro.h klic-3.003-2002-03-11/include/klic/gg_macro.h
--- klic-3.003-2002-03-09b/include/klic/gg_macro.h	Sat Mar  9 16:41:10 2002
+++ klic-3.003-2002-03-11/include/klic/gg_macro.h	Mon Mar 11 13:23:18 2002
@@ -41,7 +41,7 @@
 #define GG_GCREQUEST GENERIC_GCREQUEST
 #define GG_RETURN  do{ return g_allocp; }while(0)
 
-#define GG_TERMINATE  do{ set_heapp(g_allocp); return; }while(0)
+#define GG_TERMINATE  do{ set_heapp(g_allocp); return !0; }while(0)
 
 #define GG_SUSPEND(var) \
 do{ \
@@ -176,7 +176,7 @@
 /**********************************************************************/
 
 #define GGDEF_UNIFY() \
-static void GG_rappend(active_unify) (q GG_SELF, q GG_TERM)
+static int GG_rappend(active_unify) (q GG_SELF, q GG_TERM)
 
 #define GGDEF_SUSPEND() \
 static q \
diff -ruN klic-3.003-2002-03-09b/include/klic/gg_methtab.h klic-3.003-2002-03-11/include/klic/gg_methtab.h
--- klic-3.003-2002-03-09b/include/klic/gg_methtab.h	Sun Feb 24 14:51:46 2002
+++ klic-3.003-2002-03-11/include/klic/gg_methtab.h	Mon Mar 11 13:32:23 2002
@@ -8,10 +8,7 @@
 #ifndef _KLIC_GG_METHTAB_H_
 #define _KLIC_GG_METHTAB_H_
 
-extern q* GG_STD_UNIFY();
 extern q GG_STD_SUSPEND();
-extern long GG_STD_PRINT();
-extern q* GG_STD_GC();
 
 /* runtime/generic.c */
 extern void GD_STD_DEALLOCATE(struct data_object* GD_SELF);
@@ -23,7 +20,7 @@
 struct generator_object_method_table GG_method_table
   = {
 #ifndef GGUSE_MY_UNIFY
-  GG_STD_UNIFY ,
+#error "please GGDEF_UNIFY and GGUSE_MY_UNIFY"
 #else
   GG_rappend(active_unify) ,
 #endif
@@ -42,13 +39,13 @@
 #endif
 
 #ifndef GGUSE_MY_PRINT
- GG_STD_PRINT ,
+#error "please GGDEF_PRINT and GGUSE_MY_PRINT"
 #else
  GG_rappend(print) ,
 #endif
 
 #ifndef GGUSE_MY_GC
- GG_STD_GC ,
+#error "please GGDEF_GC and GGUSE_MY_GC"
 #else
  GG_rappend(gc) ,
 #endif
diff -ruN klic-3.003-2002-03-09b/runtime/ge_exref.c klic-3.003-2002-03-11/runtime/ge_exref.c
--- klic-3.003-2002-03-09b/runtime/ge_exref.c	Sat Mar  9 16:41:10 2002
+++ klic-3.003-2002-03-11/runtime/ge_exref.c	Mon Mar 11 13:23:28 2002
@@ -102,7 +102,7 @@
       /* fprintf(stderr, "Node:%d unify EXREF-non-EXREF", my_node); */
     }
   }
-  set_heapp(NULL);  /* Cannot unify now */
+  return 0;  /* Cannot unify now */
 }
 
 GGDEF_ENCODE()
diff -ruN klic-3.003-2002-03-09b/runtime/gg_shbusy.c klic-3.003-2002-03-11/runtime/gg_shbusy.c
--- klic-3.003-2002-03-09b/runtime/gg_shbusy.c	Sat Mar  9 12:33:13 2002
+++ klic-3.003-2002-03-11/runtime/gg_shbusy.c	Mon Mar 11 13:27:53 2002
@@ -34,12 +34,13 @@
 
   struct generator_object* gobj;
   q pair = derefone(GG_SELF);
-  if( !isref(pair) || GG_SELF != derefone(pair) ){ One_more(); return; }
+  if( !isref(pair) || GG_SELF != derefone(pair) ){ One_more(); GG_TERMINATE; }
   gobj = n_lock(GG_SELF, pair);
   if( derefone(GG_SELF) == pair ){
     n_unlock(pair, gobj);
   }
   One_more();
+  GG_TERMINATE;
 }
 
 GGDEF_GENERATE()
diff -ruN klic-3.003-2002-03-09b/runtime/gg_shvar.c klic-3.003-2002-03-11/runtime/gg_shvar.c
--- klic-3.003-2002-03-09b/runtime/gg_shvar.c	Sat Mar  9 13:22:44 2002
+++ klic-3.003-2002-03-11/runtime/gg_shvar.c	Mon Mar 11 13:27:13 2002
@@ -63,9 +63,9 @@
   struct generator_object *addi;
   Shvar *gobjp;
   q pair = derefone(GG_SELF);
-  if( !isref(pair) || GG_SELF != derefone(pair) ){ One_more(); return; }
+  if( !isref(pair) || GG_SELF != derefone(pair) ){ One_more(); GG_TERMINATE; }
   addi = n_lock(GG_SELF, pair);
-  if( pair != derefone(GG_SELF) ){ One_more(); return; }
+  if( pair != derefone(GG_SELF) ){ One_more(); GG_TERMINATE; }
 
   gobjp = (Shvar*) untag_generator_susp(addi);
   GG_SWITCH_ON_TERM(cons, atomic, func, dobj, susp);
@@ -124,7 +124,7 @@
     if( !isref(ytemp) || y != derefone(ytemp) ){
       n_unlock(temp, xaddi);
       One_more();
-      return;
+      GG_TERMINATE;
     }
     yaddi = generator_suspp(ytemp)->u.o;
     /* if yaddi is generator_susp */
@@ -145,7 +145,7 @@
 	  xaddi = n_lock(x, temp);
 	  if( temp != derefone(x) ){
 	    One_more();
-	    return;
+	    GG_TERMINATE;
 	  }
 	  xobjp = (Shvar*) untag_generator_susp(xaddi);
 	}
@@ -159,7 +159,7 @@
 	    if( derefone(y) != ytemp ){
 	      n_unlock(temp,xaddi);
 	      One_more();
-	      return;
+	      GG_TERMINATE;
 	    }
 	    yobjp = (Shvar*) untag_generator_susp(yaddi);
 	    if( yobjp->chain ){
@@ -211,7 +211,7 @@
 	    g_allocp = heapp();
 	    derefone(y) = tmpy;
 	    One_more();
-	    return;
+	    GG_TERMINATE;
 	  }
 	}else{ /* x is a simple variable */
 	  xobjp = create_genhook(tag_local(y), x);
diff -ruN klic-3.003-2002-03-09b/runtime/random.c klic-3.003-2002-03-11/runtime/random.c
--- klic-3.003-2002-03-09b/runtime/random.c	Sat Mar  9 16:41:10 2002
+++ klic-3.003-2002-03-11/runtime/random.c	Mon Mar 11 13:23:48 2002
@@ -83,7 +83,7 @@
 
 GGDEF_UNIFY()
 {
-  set_heapp(NULL);
+  return 0;
 }
 
 #define GGUSE_MY_GENERATE
diff -ruN klic-3.003-2002-03-09b/runtime/unify.c klic-3.003-2002-03-11/runtime/unify.c
--- klic-3.003-2002-03-09b/runtime/unify.c	Sat Mar  9 12:09:04 2002
+++ klic-3.003-2002-03-11/runtime/unify.c	Mon Mar 11 13:18:59 2002
@@ -86,18 +86,15 @@
     /* generator_object */
     struct generator_susp *gsusp = generator_suspp(susprecord);
     struct generator_object *gobj = untag_generator_susp(gsusp->u.o);
-    q *tempallocp;
+    int unified;
     q backpt = gsusp->backpt;
 
     set_heapp(allocp);
-    method_table_of(gobj)->active_unify(gsusp->backpt, y);
-    tempallocp = heapp();
-    if(tempallocp != NULL) {
+    unified = method_table_of(gobj)->active_unify(gsusp->backpt, y);
+    if(unified) {
       /* Unify method was succeeded */
-      allocp = tempallocp;
-/*
-      derefone(backpt) = y; 
-*/
+      allocp = heapp();
+      /* derefone(backpt) = y; */
     } else {
       /* failed */
       q tmp;
@@ -219,34 +216,29 @@
 */
 {
   declare_globals;
+  int unified;
   q* allocp = heapp();
-  q *tmpallocp;
 
   /* At first, try unify method */
   set_heapp(allocp);
-  method_table_of(untag_generator_susp(gsx->u.o))->
+  unified = method_table_of(untag_generator_susp(gsx->u.o))->
     active_unify(gsx->backpt, sy->backpt);
-  tmpallocp = heapp();
-  if(tmpallocp != (q*)0) {
+  if(unified) {
     /* succeeded */
-    allocp = tmpallocp;
-/*
-    derefone(gsx->backpt) = sy->backpt;
-*/
+    allocp = heapp();
+    /* derefone(gsx->backpt) = sy->backpt; */
   } else {
     /* unify of x is failed */
     if(is_generator_susp(sy->u)) {
       struct generator_susp *gsy = generator_suspp(sy);
-      q* tempallocp;
+      int unified;
+
       set_heapp(allocp);
-      method_table_of(untag_generator_susp(gsy->u.o))->
+      unified = method_table_of(untag_generator_susp(gsy->u.o))->
 	active_unify(gsy->backpt, gsx->backpt);
-      tempallocp = heapp();
-      if(tempallocp != (q*)0) {
-	allocp = tempallocp;
-/*
-	derefone(gsy->backpt) = gsx->backpt;
-*/
+      if(unified) {
+	allocp = heapp();
+	/* derefone(gsy->backpt) = gsx->backpt; */
       } else {
 	/* x and y are both generator,
 	   but both failed. */