Nat.sub_sub: law of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/nat.bend as Nat
Lines 706-711 of bend-mathlib@0.8.1.0/nat.bend: https://jend.leeeet.dev/read.txt?path=bend-mathlib@0.8.1.0/nat.bend&start_line=706&end_line=711

import Base

# Subtracting twice is subtracting the sum: (n - m) - k = n - (m + k).
law sub_sub:
  for n: Nat
  for m: Nat
  for k: Nat
  {Nat.sub(Nat.sub(n, m), k) == Nat.sub(n, Nat.add(m, k)) : Nat}

Uses (4):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.sub
  https://jend.leeeet.dev/definition.txt?path=bend-mathlib@0.8.1.0/nat.bend&name=zero_sub