Biimplication.java

Go to the documentation of this file.

package edu.tum.cs.logic;

import edu.tum.cs.srl.Database;

import java.util.Collection;

public class Biimplication extends ComplexFormula {
        
        public Biimplication(Collection<Formula> parts) throws Exception {
                super(parts);
                if(parts.size() != 2)
                        throw new Exception("A biimplication must have exactly two children.");
        }

        public Biimplication(Formula f1, Formula f2) {
                super(new Formula[]{f1, f2});
        }

        public String toString() {
                return "(" + children[0] + " <=> " + children[1] + ")";
        }

        @Override
        public boolean isTrue(IPossibleWorld w) {
                return children[0].isTrue(w) == children[1].isTrue(w);
        }

        @Override
        public Formula toCNF() {
                Formula c1 = new Disjunction(new Negation(children[0]), children[1]);
                Formula c2 = new Disjunction(children[0], new Negation(children[1]));
                return new Conjunction(c1, c2).toCNF();
        }
        
        @Override
        public Formula toNNF() {
                Formula c1 = new Disjunction(new Negation(children[0]), children[1]);
                Formula c2 = new Disjunction(children[0], new Negation(children[1]));
                return new Conjunction(c1, c2).toNNF();         
        }

    @Override
    public Formula simplify(Database evidence) {
        Formula c1 = new Disjunction(new Negation(children[0]), children[1]);
        Formula c2 = new Disjunction(children[0], new Negation(children[1]));
        return (new Conjunction(c1, c2)).simplify(evidence);
    }
}

---

srldb
Author(s): Dominik Jain, Stefan Waldherr, Moritz Tenorth
autogenerated on Fri Jan 11 09:58:29 2013