AIMA.Core.Logic.Propositional.Parsing.Ast.BinarySentence.getFirst C# (CSharp) Method

        public Sentence getFirst()
        {
            return first;
        }

 private Sentence transformBiConditionalSentence(BinarySentence bs)
 {
     Sentence first = new BinarySentence("=>", (Sentence)bs.getFirst()
             .accept(this, null), (Sentence)bs.getSecond().accept(this,
             null));
     Sentence second = new BinarySentence("=>", (Sentence)bs.getSecond()
             .accept(this, null), (Sentence)bs.getFirst()
             .accept(this, null));
     return new BinarySentence("AND", first, second);
 }