Deriving rules of inference
I'm going over old test results, and for whatever reason I just can't get this one into my head.
Given the proposition
determine whether it is a tautology [it is, of course], and, if it is a tautology, write the valid argument determined by it.
In other words, figure out what rule of inference can be derived from this argument. I believe it is modus tollens, but am not sure, and just can't see what method I would use to go about this. Any ideas?
Thanks to all the good people out there!