static LIST red_GetTerminatorPartnerLits(TERM Atom, LITERAL Lit,
BOOL UnitsOnly, LIST IndexList)
/**************************************************************
INPUT: An atom, a literal, a boolean flag and a list of SHARED_INDEXes.
RETURNS: A list of literals with sign complementary to <Lit>
that are unifiable with <Atom>. The literals are searched
in all SHARED_INDEXes from <IndexList>. Additionally,
if <Unitsonly> is true, only literals from unit clauses
are returned.
EFFECT: <Atom> is a copy of <Lit> where some substitution
was applied and equality literals might have been swapped.
<Lit> is just needed to check whether the unifiable
literals are complementary.
***************************************************************/
{
LIST Result, Unifiers, LitScan;
LITERAL NextLit;
Result = list_Nil();
for ( ; !list_Empty(IndexList); IndexList = list_Cdr(IndexList)) {
Unifiers = st_GetUnifier(cont_LeftContext(),
sharing_Index(list_Car(IndexList)),
cont_RightContext(), Atom);
for ( ; !list_Empty(Unifiers); Unifiers = list_Pop(Unifiers)) {
if (!term_IsVariable(list_Car(Unifiers))) {
for (LitScan = sharing_NAtomDataList(list_Car(Unifiers));
!list_Empty(LitScan); LitScan = list_Cdr(LitScan)) {
NextLit = list_Car(LitScan);
if (clause_LiteralsAreComplementary(Lit, NextLit) &&
(!UnitsOnly || clause_Length(clause_LiteralOwningClause(NextLit))==1))
/* The partner literals must have complementary sign and
if <UnitsOnly> == TRUE they must be from unit clauses. */
Result = list_Cons(NextLit, Result);
}
}
}
}
return Result;
}
static LIST inf_GetURPartnerLits(TERM Atom, LITERAL Lit,
BOOL Unit, SHARED_INDEX Index)
/**************************************************************
INPUT: An atom, a literal, a boolean flag and a SHARED_INDEX.
RETURNS: A list of literals with sign complementary to <Lit>
that are unifiable with <Atom>. If <Unit> is true,
only literals from unit clauses are returned, if <Unit>
is false, only literals from non-unit clauses are
returned.
EFFECT: <Atom> is a copy of <Lit>'s atom where some substitution
was applied and equality literals might have been swapped.
<Lit> is just needed to check whether the unifiable
literals are complementary.
***************************************************************/
{
LIST Result, Unifiers, LitScan;
LITERAL PLit;
int length;
Result = list_Nil();
Unifiers = st_GetUnifier(cont_LeftContext(), sharing_Index(Index),
cont_RightContext(), Atom);
for ( ; !list_Empty(Unifiers); Unifiers = list_Pop(Unifiers)) {
if (!term_IsVariable(list_Car(Unifiers))) {
for (LitScan = sharing_NAtomDataList(list_Car(Unifiers));
!list_Empty(LitScan); LitScan = list_Cdr(LitScan)) {
PLit = list_Car(LitScan);
length = clause_Length(clause_LiteralOwningClause(PLit));
if (clause_LiteralsAreComplementary(Lit, PLit) &&
((Unit && length==1) || (!Unit && length!=1)))
/* The partner literals must have complementary sign and
if <Unit> == TRUE they must be from unit clauses,
if <Unit> == FALSE they must be from non-unit clauses. */
Result = list_Cons(PLit, Result);
}
}
}
return Result;
}