law length_set

bend-mathlib@0.8.1.0 · list.bend:1733

import Base

1733# Setting an element does not change the length.
1734law length_set:
1735  for -a: Quant
1736  for -A: Kind(a)
1737  for xs: List<a, A>
1738  for n: Nat
1739  for -x: A
1740  {List.length(a, A, List.set(a, A, xs, n, x)) == List.length(a, A, xs) : Nat}