public static Set<DefaultRule> selectNonisomorphicDefaultRules(
Iterable<DefaultRule> defaultRules) {
List<Clause> candidates = new ArrayList<Clause>();
for (DefaultRule rule : defaultRules) {
DefaultRule preprocessed = preprocess(rule);
candidates.add(
new Clause(
Sugar.<Literal>iterable(
preprocessed.antecedent().literals(), preprocessed.consequent().literals())));
}
Matching m = new Matching();
Set<DefaultRule> retVal = new HashSet<DefaultRule>();
for (Clause c : m.nonisomorphic(candidates)) {
List<Literal> head = new ArrayList<Literal>();
List<Literal> body = new ArrayList<Literal>();
for (Literal l : c.literals()) {
Literal newLiteral =
new Literal(
l.predicate().substring(l.predicate().indexOf(":") + 1), l.isNegated(), l.arity());
for (int i = 0; i < l.arity(); i++) {
newLiteral.set(l.get(i), i);
}
if (l.predicate().startsWith("antecedent:")
|| l.predicate().startsWith(SymmetricPredicates.PREFIX + "antecedent:")) {
body.add(newLiteral);
} else {
head.add(newLiteral);
}
}
retVal.add(new DefaultRule(new Clause(body), new Clause(head)));
}
return retVal;
}
public static DefaultRule representativeSubstitution(
DefaultRule rule, List<Set<Constant>> interchangeable) {
if (rule.antecedent().variables().isEmpty()) {
return rule;
} else {
// a bit naive (but not too much), it can be improved later...
List<Literal> auxLiteralsC = new ArrayList<Literal>();
for (Variable v : rule.antecedent().variables()) {
auxLiteralsC.add(new Literal("v", v));
}
List<Literal> auxLiteralsE = new ArrayList<Literal>();
int typeIndex = 0;
for (Set<Constant> interch : interchangeable) {
int counter = 0;
for (Term t : interch) {
auxLiteralsE.add(new Literal("v", t));
if (++counter >= rule.antecedent().variables().size()) {
break;
}
}
}
Matching m = new Matching();
m.setSubsumptionMode(Matching.OI_SUBSUMPTION);
Pair<Term[], List<Term[]>> substitutions =
m.allSubstitutions(new Clause(auxLiteralsC), new Clause(auxLiteralsE), 1);
return DefaultTransformationUtils.substitute(rule, substitutions.r, substitutions.s.get(0));
}
}
public static boolean isomorphic(DefaultRule a, DefaultRule b) {
a = preprocess(a);
b = preprocess(b);
Matching m = new Matching();
Clause ca = new Clause(Sugar.iterable(a.antecedent().literals(), a.consequent().literals()));
Clause cb = new Clause(Sugar.iterable(b.antecedent().literals(), b.consequent().literals()));
return ca.variables().size() == cb.variables().size()
&& ca.literals().size() == cb.literals().size()
&& m.isomorphism(ca, cb);
}