List.take_append_drop: law of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/list.bend as List
Lines 160-166 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=160&end_line=166

import Base

# Taking n elements and appending the rest after dropping n gives the list back.
law take_append_drop:
  for -a: Quant
  for -A: Kind(a)
  for xs: List<a, A>
  for n: Nat
  {List.append(a, A, List.take(a, A, xs, n), List.drop(a, A, xs, n)) == xs : List<a, A>}

Uses (5):
  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.drop
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.take
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat