List.foldr_reverse_sym: law of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/list.bend as List
Lines 3078-3086 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=3078&end_line=3086

import Base

# A right fold over the reverse is a left fold with the arguments flipped, reversed to rewrite toward the simple side.
law foldr_reverse_sym:
  for ~a: Quant
  for ~A: Kind(a)
  for ~B: Type
  for ~f: A -> B -> B
  for xs: List<a, A>
  for -z: B
  {List.foldl(~a, ~A, ~B, ~(x => y => f(y, x)), xs, z) == List.foldr(~a, ~A, ~B, ~f, List.reverse(a, A, xs), z) : B}

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.foldl
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.foldr
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.reverse
  https://jend.leeeet.dev/definition.txt?path=bend-mathlib@0.8.1.0/list.bend&name=foldr_reverse