law append_cons_sym

bend-mathlib@0.8.1.0 · list.bend:2426

import Base

2426# Appending after a cons: (x :: xs) ++ ys = x :: (xs ++ ys), reversed to rewrite toward the simple side.
2427law append_cons_sym:
2428  for -a: Quant
2429  for -A: Kind(a)
2430  for -x: A
2431  for -xs: List<a, A>
2432  for -ys: List<a, A>
2433  {x <> List.append(a, A, xs, ys) == List.append(a, A, x <> xs, ys) : List<a, A>}