AIMA.Test.Core.Unit.Logic.FOL.KB.Data.ClauseTest.testIsTautology C# (CSharp) Method

        public void testIsTautology()
        {
            FOLDomain domain = new FOLDomain();
            domain.addConstant("A");
            domain.addPredicate("P");
            domain.addPredicate("Q");
            domain.addPredicate("R");
            domain.addFunction("F");

            FOLParser parser = new FOLParser(domain);

            // {p(f(a)),~p(f(a))}
            Clause c = new Clause();
            c.addPositiveLiteral((Predicate)parser.parse("P(F(A))"));
            Assert.IsFalse(c.isTautology());
            c.addNegativeLiteral((Predicate)parser.parse("P(F(A))"));
            Assert.IsTrue(c.isTautology());

            // {p(x),q(y),~q(y),r(z)}
            c = new Clause();
            c.addPositiveLiteral((Predicate)parser.parse("P(x)"));
            Assert.IsFalse(c.isTautology());
            c.addPositiveLiteral((Predicate)parser.parse("Q(y)"));
            Assert.IsFalse(c.isTautology());
            c.addNegativeLiteral((Predicate)parser.parse("Q(y)"));
            Assert.IsTrue(c.isTautology());
            c.addPositiveLiteral((Predicate)parser.parse("R(z)"));
            Assert.IsTrue(c.isTautology());

            // {~p(a),p(x)}
            c = new Clause();
            c.addNegativeLiteral((Predicate)parser.parse("P(A)"));
            Assert.IsFalse(c.isTautology());
            c.addPositiveLiteral((Predicate)parser.parse("P(x)"));
            Assert.IsFalse(c.isTautology());
        }