george
Posts:
800
Registered:
8/5/08


Re: If ZFC is a FORMAL THEORY ... then what is THEOREM 1 ?
Posted:
Oct 13, 2012 8:16 PM


On Oct 13, 4:30 pm, Graham Cooper <grahamcoop...@gmail.com> wrote: > You still owe me some BASE THEOREMS, otherwise all your "proofs" are > Oracular.
No, I don't. I can just say that rule "EM" (that is what I choose to call it) allows me to infer P V ~P *FROM*NOTHING*. Moreover, I can call the universal generalization of that (with P as the variable) an inference rule (if I want to) and say that if P is ANY WFF WHATSOEVER in the firstorder langauge I am using, then P V ~P is inferred, as the conclusion of this inference rule, and as a theorem, FROM NOTHING. That does NOT make anything "oracular" and it does NOT make anything a "logical axiom".
I can [AND DO] JUST say that it is an inference rule that any instance of a propositional tautology is a theorem.

