Theorem ifneg ≪ | index | src | ≫

pub theorem ifneg (p: wff) (a b: nat): $ ~p -> if p a b = b $;

~p -> (ifp p (n = a) (n = b) <-> n = b)

~p -> the {n | ifp p (n = a) (n = b)} = b

~p -> if p a b = b

Axiom use