SYMBOL cont_TermMaxVar(CONTEXT Context, TERM Term)
/*********************************************************
INPUT: A context and a term.
RETURNS: The maximal variable in <Term> with respect to
the bindings in <Context>
********************************************************/
{
LIST scan;
SYMBOL result;
#ifdef CHECK
if (!term_IsTerm(Term)) {
misc_StartErrorReport();
misc_ErrorReport("\n In cont_TermMaxVar: Input term is corrupted.\n");
misc_FinishErrorReport();
}
#endif
Term = cont_Deref(&Context,Term);
result = symbol_Null();
if (term_IsStandardVariable(Term)) {
if (term_TopSymbol(Term) > result)
result = term_TopSymbol(Term);
} else {
for (scan = term_ArgumentList(Term); !list_Empty(scan); scan = list_Cdr(scan)) {
SYMBOL max = cont_TermMaxVar(Context, list_Car(scan));
if (max > result)
result = max;
}
}
return result;
}
static int kbo_ContCompVarCondAndWeightIntern(CONTEXT Context, TERM Term, int Index)
/**************************************************************
INPUT:
EFFECT:
***************************************************************/
{
int Weight;
Weight = 0;
Term = cont_Deref(&Context,Term);
if (term_IsStandardVariable(Term)) {
ord_VARCOUNT[term_TopSymbol(Term)][Index]++;
Weight += kbo_MINWEIGHT;
}
else {
LIST Scan;
Weight += symbol_Weight(term_TopSymbol(Term));
for (Scan=term_ArgumentList(Term); !list_Empty(Scan); Scan=list_Cdr(Scan))
Weight += kbo_ContCompVarCondAndWeightIntern(Context, list_Car(Scan), Index);
}
return Weight;
}
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;
}