Nat.add_left_comm: law of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/nat.bend as Nat
Lines 86-91 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=86&end_line=91

import Base

# Left commutativity of addition: a + (b + c) = b + (a + c).
law add_left_comm:
  for a: Nat
  for b: Nat
  for -c: Nat
  {Nat.add(a, Nat.add(b, c)) == Nat.add(b, Nat.add(a, c)) : Nat}

Uses (4):
  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=bend-mathlib@0.8.1.0/nat.bend&name=add_succ