public void TrueExample1()
        {
            Disjunction disj = new Disjunction(A, B);
            Conjunction conj = new Conjunction(disj, C);

            Assert.True(conj.Is_NNF());
        }
        public void NestedExample()
        {
            Disjunction disj  = new Disjunction(A, B);
            Disjunction disj1 = new Disjunction(disj, A);
            Conjunction conj  = new Conjunction(disj1, A);
            Conjunction conj1 = new Conjunction(new Negation(conj), A);

            Assert.False(conj1.Is_NNF());
            Assert.True(conj.Is_NNF());
        }
        public void TrueExample4()
        {
            Conjunction conj = new Conjunction(A, new Negation(B));

            Assert.True(conj.Is_NNF());
        }