List.last_append_singleton_sym: law of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/list.bend as List
Lines 2972-2978 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=2972&end_line=2978

import Base

# The last element of xs ++ [x] is x, reversed to rewrite toward the simple side.
law last_append_singleton_sym:
  for -a: Quant
  for -A: Kind(a)
  for xs: List<a, A>
  for -x: A
  {Some{x} == List.last(a, A, List.append(a, A, xs, [x])) : Maybe<a, A>}

Uses (6):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.sym
  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.last
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=bend-mathlib@0.8.1.0/list.bend&name=last_append_singleton