law nat_mul_four_sym

bend-mathlib@0.8.1.0 · algebra.bend:415

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

415# Nat multiplication's middle-four interchange (the same statement as MNat.mul_mul_mul_comm), reversed to rewrite toward the simple side.
416law nat_mul_four_sym:
417  for +a: Nat
418  for +b: Nat
419  for +c: Nat
420  for +d: Nat
421  {Nat.mul(Nat.mul(a, c), Nat.mul(b, d)) == Nat.mul(Nat.mul(a, b), Nat.mul(c, d)) : Nat}