Theorem sbnet ≪ | index | src | ≫

theorem sbnet {x: nat} (a: nat) (b: nat x) (c: nat):
  $ A. x (x = a -> b = c) -> N[a / x] b = c $;

FN/ x c

A. x (x = a -> b = c) -> N[a / x] b = c

Axiom use