law append_assoc

bend-mathlib@0.8.1.0 · list.bend:32

import Base

32# Append is associative: (xs ++ ys) ++ zs = xs ++ (ys ++ zs).
33law append_assoc:
34  for -a: Quant
35  for -A: Kind(a)
36  for xs: List<a, A>
37  for -ys: List<a, A>
38  for -zs: List<a, A>
39  {List.append(a, A, List.append(a, A, xs, ys), zs) == List.append(a, A, xs, List.append(a, A, ys, zs)) : List<a, A>}