Recent content by jax122

Thank you so much. That explanation makes complete sense. However, I am having trouble formalizing the notion of "since X and Y have opposite truth values, X and -Y have equal truth values". Any suggestions of how to do that via proof? Do I first need to derive X<->Y or should my first...

I agree completely that is seems intuitive that the equation is false. However, I know for a fact that the equation is a tautology. I am using a proofs program that indicates that (X <-> Y) v (X <-> -Y) is a tautology. I believe it is some version of X v -X/law of the excluded middle. Any...

Hey everyone, Thanks for the help in advance. I am having trouble deriving a tautology from no premises. I am trying to derive: (X <-> Y) v (X <-> -Y) "-" meaning not. However, I keep getting stuck. It seems very similar to the Law of the Excluded Middle but I am having trouble...