law nat_add_four_sym

bend-mathlib@0.8.1.0 · algebra.bend:384

import Base
import bend-mathlib@0.8.1.0/nat.bend as MNat

384# Nat addition's middle-four interchange (the same statement as MNat.add_add_add_comm), reversed to rewrite toward the simple side.
385law nat_add_four_sym:
386  for +a: Nat
387  for +b: Nat
388  for +c: Nat
389  for +d: Nat
390  {Nat.add(Nat.add(a, c), Nat.add(b, d)) == Nat.add(Nat.add(a, b), Nat.add(c, d)) : Nat}