law take_succ

bend-mathlib@0.8.1.0 · list.bend:2102

import Base

2102# Taking n + 1 elements of a cons keeps its head and takes n from its tail.
2103law take_succ:
2104  for -a: Quant
2105  for -A: Kind(a)
2106  for -x: A
2107  for -xs: List<a, A>
2108  for -n: Nat
2109  {List.take(a, A, x <> xs, 1n+n) == x <> List.take(a, A, xs, n) : List<a, A>}