law add_sub_add_left

bend-mathlib@0.8.1.0 · nat.bend:2272

import Base

2272# A common left summand cancels in a difference: (k + n) - (k + m) = n - m.
2273law add_sub_add_left:
2274  for k: Nat
2275  for -n: Nat
2276  for -m: Nat
2277  {Nat.sub(Nat.add(k, n), Nat.add(k, m)) == Nat.sub(n, m) : Nat}