Nat.sub_sub_sym: law of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/nat.bend as Nat
Lines 4055-4060 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=4055&end_line=4060

import Base

# Subtracting twice is subtracting the sum: (n - m) - k = n - (m + k), reversed to rewrite toward the simple side.
law sub_sub_sym:
  for n: Nat
  for m: Nat
  for k: Nat
  {Nat.sub(n, Nat.add(m, k)) == Nat.sub(Nat.sub(n, m), k) : Nat}

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.sym
  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=sub_sub