static LIST st_TraverseTreeGenPreTest(CONTEXT IndexContext,
st_INDEX StIndex,
st_MINMAX MinMax)
/**************************************************************
INPUT:
RETURNS:
EFFECTS:
***************************************************************/
{
int Save;
LIST Result, CurrentList;
st_INDEX CurrentNode;
/* PREPARE TRAVERSAL */
Save = stack_Bottom();
Result = list_Nil();
CurrentList = StIndex->subnodes;
cont_StartBinding();
for (;;) {
/* BACKTRACK A BIG STEP */
if (list_Empty(CurrentList)) {
cont_StopAndBackTrack();
if (stack_Empty(Save))
return Result;
CurrentList = stack_PopResult();
}
/* DESCENDING */
for (CurrentNode = (st_INDEX)list_Car(CurrentList);
(MinMax >= st_Min(CurrentNode)) &&
subst_Match(IndexContext, CurrentNode->subst);
CurrentList = CurrentNode->subnodes,
CurrentNode = (st_INDEX)list_Car(CurrentList))
if (st_IsLeaf(CurrentNode)) {
Result = list_Append(CurrentNode->entries, Result);
break;
} else if (list_Cdr(CurrentList)) {
stack_Push(list_Cdr(CurrentList));
cont_StartBinding();
} else
cont_StopAndStartBinding();
/* BACKTRACK LEAF OR INNER NODE */
CurrentList = list_Cdr(CurrentList);
cont_BackTrackAndStart();
}
}
static int kbo_CompVarCondAndWeight(TERM Term1, BOOL *VarCond1, TERM Term2, BOOL *VarCond2)
/**************************************************************
INPUT: Two terms and two pointers to booleans.
EFFECT: Sets the booleans with respect to the kbo variable condition.
Computes the kbo weight difference.
***************************************************************/
{
SYMBOL MaxVar1,MaxVar2;
TERM Term;
LIST Scan;
int i,Stack,Weight;
*VarCond1 = *VarCond2 = TRUE;
MaxVar1 = term_MaxVar(Term1);
MaxVar2 = term_MaxVar(Term2);
Stack = stack_Bottom();
Weight = 0;
if (MaxVar1 < MaxVar2)
MaxVar1 = MaxVar2;
for (i = 0; i <= MaxVar1; i++) {
ord_VARCOUNT[i][0] = 0;
ord_VARCOUNT[i][1] = 0;
}
Term = Term1;
if (term_IsStandardVariable(Term)) {
ord_VARCOUNT[term_TopSymbol(Term)][0]++;
Weight += kbo_MINWEIGHT;
}
else {
Weight += symbol_Weight(term_TopSymbol(Term));
if (term_IsComplex(Term))
stack_Push(term_ArgumentList(Term));
}
while (!stack_Empty(Stack)) {
Scan = stack_Top();
Term = (TERM)list_Car(Scan);
stack_RplacTop(list_Cdr(Scan));
if (term_IsStandardVariable(Term)) {
Weight += kbo_MINWEIGHT;
ord_VARCOUNT[term_TopSymbol(Term)][0]++;
}
else {
Weight += symbol_Weight(term_TopSymbol(Term));
if (term_IsComplex(Term))
stack_Push(term_ArgumentList(Term));
}
while (!stack_Empty(Stack) && list_Empty(stack_Top()))
stack_Pop();
}
Term = Term2;
if (term_IsStandardVariable(Term)) {
Weight -= kbo_MINWEIGHT;
ord_VARCOUNT[term_TopSymbol(Term)][1]++;
}
else {
Weight -= symbol_Weight(term_TopSymbol(Term));
if (term_IsComplex(Term))
stack_Push(term_ArgumentList(Term));
}
while (!stack_Empty(Stack)) {
Scan = stack_Top();
Term = (TERM)list_Car(Scan);
stack_RplacTop(list_Cdr(Scan));
if (term_IsStandardVariable(Term)) {
Weight -= kbo_MINWEIGHT;
ord_VARCOUNT[term_TopSymbol(Term)][1]++;
}
else {
Weight -= symbol_Weight(term_TopSymbol(Term));
if (term_IsComplex(Term))
stack_Push(term_ArgumentList(Term));
}
while (!stack_Empty(Stack) && list_Empty(stack_Top()))
stack_Pop();
}
for (i = 0; i <= MaxVar1; i++) {
if (ord_VARCOUNT[i][0] < ord_VARCOUNT[i][1]) {
*VarCond1 = FALSE;
if (!*VarCond2)
return Weight;
}
if (ord_VARCOUNT[i][0] > ord_VARCOUNT[i][1]) {
*VarCond2 = FALSE;
if (!*VarCond1)
return Weight;
}
}
return Weight;
}
