public FormulaAnalysis(Formula formula) {
f = formula;
/*
* Converts the Formula to Disjunctive Normal Form and collects the clauses
*/
formula = formula.getDNF();
Formula[] rawClauses;
if (formula instanceof Disjunction) {
Disjunction disj = ((Disjunction) formula).flatten();
rawClauses = new Formula[disj.getNoFormulas()];
for (int i = 0; i < rawClauses.length; i++) rawClauses[i] = disj.get(i);
} else {
rawClauses = new Formula[] {formula};
}
/*
* Processes each clause
*/
clauses = new ArrayList<DNFClause>(rawClauses.length);
List<Atom> posLiterals = new ArrayList<Atom>(4);
List<Atom> negLiterals = new ArrayList<Atom>(4);
for (int i = 0; i < rawClauses.length; i++) {
/*
* Extracts the positive and negative literals from the clause
*/
if (rawClauses[i] instanceof Conjunction) {
Conjunction c = ((Conjunction) rawClauses[i]).flatten();
for (int j = 0; j < c.getNoFormulas(); j++) {
if (c.get(j) instanceof Atom) {
posLiterals.add((Atom) c.get(j));
} else if (c.get(j) instanceof Negation) {
Negation n = (Negation) c.get(j);
if (n.getFormula() instanceof Atom) {
negLiterals.add((Atom) n.getFormula());
} else {
throw new IllegalStateException(
"Unexpected sub-Formula. Formula was not in flattened Disjunctive Normal Form.");
}
} else {
throw new IllegalStateException(
"Unexpected sub-Formula. Formula was not in flattened Disjunctive Normal Form.");
}
}
} else if (rawClauses[i] instanceof Atom) {
posLiterals.add((Atom) rawClauses[i]);
} else if (rawClauses[i] instanceof Negation) {
Negation n = (Negation) rawClauses[i];
if (n.getFormula() instanceof Atom) {
negLiterals.add((Atom) n.getFormula());
} else {
throw new IllegalStateException(
"Unexpected sub-Formula. Formula was not in flattened Disjunctive Normal Form.");
}
} else {
throw new IllegalStateException(
"Unexpected sub-Formula. Formula was not in flattened Disjunctive Normal Form.");
}
/*
* Stores the DNFClause
*/
clauses.add(new DNFClause(posLiterals, negLiterals));
posLiterals.clear();
negLiterals.clear();
}
}
