def one_less

minebender-game@1.0.0.0 · proof_speed.bend:435

import Base
import minebender-game@1.0.0.0/proof_base.bend as P

435def one_less(+a: Nat, +b: Nat, +f: Nat, e1: {a == f : Nat}, e2: {a == 1n+b : Nat}) -> {b == Nat.sub(f, 1n) : Nat}:
436  %e1 : {b == Nat.sub(_, 1n) : Nat}
437  %Equal.sym(Nat, a, 1n+b, e2) : {b == Nat.sub(_, 1n) : Nat}
438  Equal.sym(Nat, Nat.sub(b, 0n), b, P.sub_zero(b))