List.replicate_add_sym: law of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/list.bend as List
Lines 2716-2722 of bend-mathlib@0.8.1.0/list.bend: https://jend.leeeet.dev/read.txt?path=bend-mathlib@0.8.1.0/list.bend&start_line=2716&end_line=2722

import Base

# Replicating m + n times appends m copies to n copies, reversed to rewrite toward the simple side.
law replicate_add_sym:
  for -A: Data
  for m: Nat
  for -n: Nat
  for -x: A
  {List.append(&2, A, List.replicate(A, m, x), List.replicate(A, n, x)) == List.replicate(A, Nat.add(m, n), x) : List<&2, A>}

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.sym
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.append
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.replicate
  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/list.bend&name=replicate_add