private static MultiMap<Variable, Variable> surelyDifferent(DefaultRule rule) {
Clause body = rule.antecedent();
Clause head = rule.consequent();
final MultiMap<Variable, Variable> different = new MultiMap<Variable, Variable>();
for (Literal literal :
Sugar.union(
body.getLiteralsByPredicate(SpecialBinaryPredicates.NEQ),
body.getLiteralsByPredicate(SpecialBinaryPredicates.GT),
body.getLiteralsByPredicate(SpecialBinaryPredicates.LT),
body.getLiteralsByPredicate(SpecialVarargPredicates.ALLDIFF),
head.getLiteralsByPredicate(SpecialBinaryPredicates.NEQ),
head.getLiteralsByPredicate(SpecialBinaryPredicates.GT),
head.getLiteralsByPredicate(SpecialBinaryPredicates.LT),
head.getLiteralsByPredicate(SpecialVarargPredicates.ALLDIFF))) {
for (Term a : literal.terms()) {
if (a instanceof Variable) {
Variable v1 = (Variable) a;
for (Term b : literal.terms()) {
if (b instanceof Variable) {
Variable v2 = (Variable) b;
if (v1 != v2) {
different.put(v1, v2);
}
}
}
}
}
}
return different;
}
