CLAUSE red_Terminator(CLAUSE RedClause, NAT n, SHARED_INDEX WoIndex,
SHARED_INDEX UsIndex, FLAGSTORE Flags,
PRECEDENCE Precedence)
/**************************************************************
INPUT: A clause, two shared indexes, a number <n>
restricting the number of non-unit clauses in
a possible terminator situation, a flag store
and a precedence.
RETURNS: An empty clause if a terminator with at most <n>
non-unit clauses is found, NULL otherwise.
EFFECT: See also description of red_SearchTerminator.
***************************************************************/
{
LIST Rest, IndexList;
CLAUSE Result;
if (clause_Length(RedClause) > 1) /* non-unit clause */
n--;
/* Pass the indexes as a list to sub-functions */
IndexList = list_Cons(WoIndex, list_List(UsIndex));
Rest = clause_GetLiteralList(RedClause);
Result = red_SearchTerminator(n, Rest, list_Nil(), subst_Nil(),
clause_MaxVar(RedClause), IndexList, Flags,
Precedence);
/* cleanup */
list_Delete(IndexList);
list_Delete(Rest);
return Result;
}
static void cc_InitData(CLAUSE clause)
/***************************************************************
INPUT: the clause to investigate
EFFECT: pushes clause's atoms and their subterms on the
pending stack, initializes each predecessor list with
the list containing only a term's father, and unions
the equivalence classes of the terms of the same
antecedent equation
***************************************************************/
{
int last, actno, i, ld;
TERM atom;
RAS cdr, size;
cc_SetCars(ras_InitWithSize(cc_GetCars(), cc_RASSTDSIZE));
cc_SetPending(ras_InitWithSize(cc_GetPending(), cc_RASSTDSIZE));
ras_FastPush(cc_GetCars(), term_Null()); /* "true" has no predecessors */
actno = 1;
last = clause_LastLitIndex(clause);
for (i = clause_FirstLitIndex(); i <= last; i++) {
atom = clause_GetLiteralAtom(clause, i);
if (fol_IsEquality(atom)) {
actno = cc_Number(actno, term_FirstArgument(atom), term_Null());
actno = cc_Number(actno, term_SecondArgument(atom), term_Null());
}
else
actno = cc_Number(actno, atom, term_Null());
}
cc_SetPartition(part_Init(cc_GetPartition(), actno));
cc_SetTable(table_Init(cc_GetTable(), symbol_ActIndex() - 1,
clause_MaxVar(clause), actno - 1));
cdr = ras_InitWithSize(cc_GetCdrs(), actno);
size = ras_InitWithSize(cc_GetSizes(), actno);
for (i = 0; i < actno; i++) {
ras_FastPush(cdr, (POINTER) i); /* form a cycle */
ras_FastPush(size, (POINTER) (cc_GetCar(i) == term_Null()? 0 : 1));
}
cc_SetCdrs(cdr);
cc_SetSizes(size);
/* compute ceil(ld(actno)) avoiding mathbib-logarithm's rounding errors: */
for (ld = 0, i = actno - 1; i > 0; i >>= 1)
ld++;
cc_SetCombine(ras_InitWithSize(cc_GetCombine(), actno * ld + 1));
/* for every antecedent equation union equivalence classes of its terms */
/* (a non-equational atom is represented as the equation atom = "true"): */
last = clause_LastAntecedentLitIndex(clause);
for (i = clause_FirstLitIndex(); i <= last; i++) {
atom = clause_GetLiteralAtom(clause, i);
if (fol_IsEquality(atom))
cc_Union(term_Size(term_FirstArgument(atom)), /* clause not shared, therefore */
term_Size(term_SecondArgument(atom))); /* here no cc_Find needed */
else
cc_Union(term_Size(atom), part_Find(cc_GetPartition(), cc_NOOFTRUE));
}
}
void ana_AnalyzeProblem(PROOFSEARCH Search, LIST Clauses)
/**************************************************************
INPUT: A proofsearch object and a list of clauses.
RETURNS: Void.
EFFECT: Analyzes the clauses and sets the analyze variables.
Recomputes the weight for the clauses.
<Search> is modified according to clauses: non trivial domain number
is set
***************************************************************/
{
CLAUSE Clause;
ana_EQUATIONS = FALSE;
ana_PEQUATIONS = FALSE; /* Defaults for properties */
ana_NEQUATIONS = FALSE;
ana_FUNCTIONS = FALSE;
ana_FINDOMAIN = FALSE;
ana_NONTRIVDOMAIN = FALSE;
ana_MONADIC = FALSE;
ana_NONMONADIC = FALSE;
ana_PROP = FALSE;
ana_GROUND = FALSE;
ana_SORTRES = FALSE;
ana_USORTRES = FALSE;
ana_NONUNIT = FALSE;
ana_CONGROUND = TRUE;
ana_AXIOMCLAUSES = 0;
ana_CONCLAUSES = 0;
ana_NONHORNCLAUSES = 0;
list_Delete(ana_FINITEMONADICPREDICATES);
ana_FINITEMONADICPREDICATES = list_Nil();
if (list_Empty(Clauses))
return;
ana_FINITEMONADICPREDICATES = clause_FiniteMonadicPredicates(Clauses);
while (!list_Empty(Clauses)) {
Clause = (CLAUSE)list_Car(Clauses);
clause_UpdateWeight(Clause, prfs_Store(Search));
if (clause_GetFlag(Clause,CONCLAUSE))
ana_CONCLAUSES++;
else
ana_AXIOMCLAUSES++;
if (clause_NumOfSuccLits(Clause) > 1)
ana_NONHORNCLAUSES++;
if (ana_CONGROUND && clause_GetFlag(Clause,CONCLAUSE) &&
clause_MaxVar(Clause) != symbol_GetInitialStandardVarCounter())
ana_CONGROUND = FALSE;
if (!ana_PEQUATIONS && clause_ContainsPositiveEquations(Clause)) {
ana_PEQUATIONS = TRUE;
}
if (!ana_NEQUATIONS && clause_ContainsNegativeEquations(Clause)) {
ana_NEQUATIONS = TRUE;
}
if (!ana_MONADIC || !ana_NONMONADIC || !ana_PROP || !ana_GROUND)
clause_ContainsFolAtom(Clause,&ana_PROP,&ana_GROUND,&ana_MONADIC,&ana_NONMONADIC);
if (!ana_FUNCTIONS && clause_ContainsFunctions(Clause)) {
ana_FUNCTIONS = TRUE;
}
if (!ana_FINDOMAIN && clause_ImpliesFiniteDomain(Clause)) {
ana_FINDOMAIN = TRUE;
}
if (!ana_NONTRIVDOMAIN && clause_ImpliesNonTrivialDomain(Clause)) {
prfs_SetNonTrivClauseNumber(Search, clause_Number(Clause));
ana_NONTRIVDOMAIN = TRUE;
}
if (!ana_NONUNIT && clause_Length(Clause) > 1) {
ana_NONUNIT = TRUE;
}
if (!ana_SORTRES || !ana_USORTRES)
clause_ContainsSortRestriction(Clause,&ana_SORTRES,&ana_USORTRES);
Clauses = list_Cdr(Clauses);
}
ana_PUREEQUATIONAL = ((ana_PEQUATIONS || ana_NEQUATIONS) && !ana_MONADIC &&
!ana_NONMONADIC && !ana_PROP && !ana_GROUND);
ana_EQUATIONS = (ana_PEQUATIONS || ana_NEQUATIONS);
ana_PUREPROPOSITIONAL = (!ana_PEQUATIONS && !ana_NEQUATIONS &&!ana_MONADIC &&
!ana_NONMONADIC && ana_PROP);
}
LIST inf_URResolution(CLAUSE Clause, SHARED_INDEX Index, FLAGSTORE Flags,
PRECEDENCE Precedence)
/**************************************************************
INPUT: A clause, a shared index, a flag store and a precedence.
RETURNS: The list of UR resolution resolvents.
EFFECT: The flag store and the precedence are needed to create
the resolvents.
***************************************************************/
{
LIST Result;
if (clause_Length(Clause) != 1) {
/* Clause isn't unit clause */
Result = inf_NonUnitURResolution(Clause, -1, list_Nil(), subst_Nil(),
clause_MaxVar(Clause), Index, Flags,
Precedence);
}
else {
/* Clause is unit clause, so search partner literals in non-unit clauses */
LITERAL Lit, PLit;
TERM Atom;
LIST Partners, FoundMap;
SYMBOL MaxVar, PMaxVar;
SUBST LeftSubst, RightSubst;
CLAUSE PClause;
int PLitInd;
BOOL Swapped;
Result = list_Nil();
Lit = clause_GetLiteral(Clause, clause_FirstLitIndex());
Atom = term_Copy(clause_LiteralAtom(Lit));
Swapped = FALSE;
/* The following 'endless' loop runs twice for equality literals */
/* and only once for other literals. */
while (TRUE) {
/* Get complementary literals from non-unit clauses */
Partners = inf_GetURPartnerLits(Atom, Lit, FALSE, Index);
for ( ; !list_Empty(Partners); Partners = list_Pop(Partners)) {
PLit = list_Car(Partners);
PLitInd = clause_LiteralGetIndex(PLit);
PClause = clause_LiteralOwningClause(PLit); /* non-unit clause */
PMaxVar = clause_MaxVar(PClause);
term_StartMaxRenaming(PMaxVar);
term_Rename(Atom); /* Rename atom from unit clause */
MaxVar = term_MaxVar(Atom);
if (symbol_GreaterVariable(PMaxVar, MaxVar))
MaxVar = PMaxVar;
/* Get the substitution */
cont_Check();
unify_UnifyNoOC(cont_LeftContext(), clause_LiteralAtom(PLit),
cont_RightContext(), Atom);
subst_ExtractUnifier(cont_LeftContext(), &LeftSubst,
cont_RightContext(), &RightSubst);
cont_Reset();
/* We don't need the substitution for the unit clause */
subst_Delete(RightSubst);
FoundMap = list_List(list_PairCreate(PLit, Lit));
Result = list_Nconc(inf_NonUnitURResolution(PClause, PLitInd, FoundMap,
LeftSubst, MaxVar, Index,
Flags, Precedence),
Result);
list_DeletePairList(FoundMap);
subst_Delete(LeftSubst);
}
/* loop control */
if (!fol_IsEquality(Atom) || Swapped)
break;
else {
term_EqualitySwap(Atom);
Swapped = TRUE;
}
} /* end of endless loop */
term_Delete(Atom);
}
return Result;
}
