Nat.add_left_comm_sym: law of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/nat.bend as Nat
Lines 3884-3889 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=3884&end_line=3889

import Base

# Left commutativity of addition: a + (b + c) = b + (a + c), reversed to rewrite toward the simple side.
law add_left_comm_sym:
  for a: Nat
  for b: Nat
  for -c: Nat
  {Nat.add(b, Nat.add(a, c)) == Nat.add(a, Nat.add(b, 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_left_comm