BOOL kbo_ContGreater(CONTEXT Context1, TERM Term1, CONTEXT Context2, TERM Term2)
/**************************************************************
INPUT: Two contexts and two terms.
RETURNS: TRUE, if Term1 is greater than Term2 wrt the kbo with
the actual precedence kbo_Prec and the given symbol_Weights
CAUTION: The precedence from the order module is used to determine
the precedence of symbols!
***************************************************************/
{
int WeightDiff;
BOOL T1VarCond, T2VarCond;
#ifdef CHECK
if ((!term_IsTerm(Term1)) || (!term_IsTerm(Term2)) ) {
misc_StartErrorReport();
misc_ErrorReport("\n In kbo_ContGreater:");
misc_ErrorReport("\n Illegal input.");
misc_FinishErrorReport();
}
#endif
WeightDiff = kbo_ContCompVarCondAndWeight(Context1, Term1, &T1VarCond, Context2, Term2, &T2VarCond);
if (T1VarCond) {
if (WeightDiff > 0)
return TRUE;
else if (WeightDiff == 0)
return kbo_ContGreaterCompareStruc(Context1,Term1,Context2,Term2);
}
return FALSE;
}
BOOL cont_TermEqual(CONTEXT Context1, TERM Term1, CONTEXT Context2, TERM Term2)
/*********************************************************
INPUT: Two terms and two contexts.
RETURNS: TRUE iff the two terms are equal, where
variables are interpreted with respect to
the bindings in the contexts.
********************************************************/
{
#ifdef CHECK
if (!(term_IsTerm(Term1) && term_IsTerm(Term2))) {
misc_StartErrorReport();
misc_ErrorReport("\n In cont_TermEqual: Input terms are corrupted.\n");
misc_FinishErrorReport();
}
#endif
Term1 = cont_Deref(&Context1,Term1);
Term2 = cont_Deref(&Context2,Term2);
if (!term_EqualTopSymbols(Term1, Term2))
return FALSE;
else if (term_ArgumentList(Term1)) {
LIST Scan1, Scan2;
for (Scan1=term_ArgumentList(Term1), Scan2=term_ArgumentList(Term2);
list_Exist(Scan1) && list_Exist(Scan2);
Scan1=list_Cdr(Scan1), Scan2=list_Cdr(Scan2))
if (!cont_TermEqual(Context1,list_Car(Scan1), Context2,list_Car(Scan2)))
return FALSE;
return (list_Empty(Scan1) ? list_Empty(Scan2) : FALSE);
} else
return TRUE;
}
ord_RESULT kbo_ContCompare(CONTEXT Context1, TERM Term1, CONTEXT Context2, TERM Term2)
/**************************************************************
INPUT: Two contexts and two terms.
RETURNS: ord_UNCOMPARABLE, if Term1 and Term2 are uncomparable because of
different variables,
ord_EQUAL, if Term1 and Term2 are comparable and have the
same weight,
ord_GREATER_THAN, if Term1 is greater than Term2 wrt the kbo with
the actual precedence kbo_Prec and the given
symbol_Weights,
ord_SMALLER_THAN, else.
The Terms are interpreted with respect to the contexts.
CAUTION: The precedence from the order module is used to determine
the precedence of symbols!
***************************************************************/
{
int WeightDiff;
BOOL T1VarCond, T2VarCond;
ord_RESULT Result;
#ifdef CHECK
if (!term_IsTerm(Term1) || !term_IsTerm(Term2)) {
misc_StartErrorReport();
misc_ErrorReport("\n In kbo_Compare:");
misc_ErrorReport("\n Illegal input.");
misc_FinishErrorReport();
}
#endif
WeightDiff = kbo_ContCompVarCondAndWeight(Context1, Term1, &T1VarCond, Context2, Term2, &T2VarCond);
if (T1VarCond && !T2VarCond)
return kbo_ContCompareStruc(Context1,Term1,Context2,Term2,WeightDiff);
if (!T1VarCond && T2VarCond)
return ord_Not(kbo_ContCompareStruc(Context2,Term2,Context1,Term1,-WeightDiff));
if (T1VarCond && T2VarCond) {
Result = kbo_ContCompareStruc(Context1,Term1,Context2,Term2,WeightDiff);
if (Result == ord_UNCOMPARABLE)
return ord_Not(kbo_ContCompareStruc(Context2,Term2,Context1,Term1,-WeightDiff));
else
return Result;
}
return ord_UNCOMPARABLE;
}
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;
}
BOOL cont_TermEqual(CONTEXT GlobalContext1, CONTEXT TermContext1, TERM Term1,
CONTEXT GlobalContext2, CONTEXT TermContext2, TERM Term2)
/*********************************************************
INPUT: Two terms and two local contexts for the terms and
two global contexts
RETURNS: TRUE iff the two terms are equal, where
variables are interpreted with respect to
the bindings in the contexts.
CAUTION: Variables of <Term1> and <Term2> are bound in
<TermContext1> and <TermContext2> respectively and
the index variables are bound in <GlobalContext1>
and <GlobalContext2> respectively.
********************************************************/
{
#ifdef CHECK
if (!(term_IsTerm(Term1) && term_IsTerm(Term2))) {
misc_StartErrorReport();
misc_ErrorReport("\n In cont_TermEqual: Input terms are corrupted.\n");
misc_FinishErrorReport();
}
#endif
Term1 = cont_Deref(GlobalContext1,&TermContext1,Term1);
Term2 = cont_Deref(GlobalContext2,&TermContext2,Term2);
if (!term_EqualTopSymbols(Term1, Term2))
return FALSE;
else if (term_ArgumentList(Term1)) {
LIST Scan1, Scan2;
for (Scan1=term_ArgumentList(Term1), Scan2=term_ArgumentList(Term2);
list_Exist(Scan1) && list_Exist(Scan2);
Scan1=list_Cdr(Scan1), Scan2=list_Cdr(Scan2))
if (!cont_TermEqual(GlobalContext1, TermContext1,list_Car(Scan1),
GlobalContext2, TermContext2,list_Car(Scan2)))
return FALSE;
return (list_Empty(Scan1) ? list_Empty(Scan2) : FALSE);
} else
return TRUE;
}
BOOL cont_TermEqualModuloBindings(CONTEXT IndexContext, CONTEXT CtL, TERM TermL,
CONTEXT CtR, TERM TermR)
/*********************************************************
INPUT: Two contexts, two terms.
RETURNS: The boolean value TRUE if the terms are equal.
CAUTION: EQUAL FUNCTION- OR PREDICATE SYMBOLS SHARE THE
SAME ARITY. THIS IS NOT VALID FOR JUNCTORS!
*******************************************************/
{
#ifdef CHECK
if (!(term_IsTerm(TermL) && term_IsTerm(TermR))) {
misc_StartErrorReport();
misc_ErrorReport("\n In cont_TermEqualModuloBindings: Input terms are corrupted.\n");
misc_FinishErrorReport();
}
#endif
while (term_IsVariable(TermL)) {
SYMBOL TermTop;
TermTop = term_TopSymbol(TermL);
if (symbol_IsIndexVariable(TermTop))
CtL = IndexContext;
else if (CtL == cont_InstanceContext())
break;
if (cont_VarIsBound(CtL, TermTop)) {
CONTEXT CHelp;
CHelp = cont_ContextBindingContext(CtL, TermTop);
TermL = cont_ContextBindingTerm(CtL, TermTop);
CtL = CHelp;
} else
break;
}
while (term_IsVariable(TermR)) {
SYMBOL TermTop;
TermTop = term_TopSymbol(TermR);
if (symbol_IsIndexVariable(TermTop))
CtR = IndexContext;
else if (CtR == cont_InstanceContext())
break;
if (cont_VarIsBound(CtR, TermTop)) {
CONTEXT CHelp;
CHelp = cont_ContextBindingContext(CtR, TermTop);
TermR = cont_ContextBindingTerm(CtR, TermTop);
CtR = CHelp;
} else
break;
}
if (!term_EqualTopSymbols(TermL, TermR))
return FALSE;
else
if (term_IsVariable(TermL)) {
if (CtL == CtR)
return TRUE;
else
return FALSE;
}
else
if (term_IsComplex(TermL)) {
LIST ScanL, ScanR;
for (ScanL=term_ArgumentList(TermL), ScanR=term_ArgumentList(TermR);
list_Exist(ScanL) && list_Exist(ScanR);
ScanL=list_Cdr(ScanL), ScanR=list_Cdr(ScanR))
if (!cont_TermEqualModuloBindings(IndexContext, CtL, list_Car(ScanL),
CtR, list_Car(ScanR)))
return FALSE;
return (list_Empty(ScanL) ? list_Empty(ScanR) : FALSE);
}
else
return TRUE;
}
