List.drop_drop_sym: law of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/list.bend as List
Lines 2366-2373 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=2366&end_line=2373

import Base

# Dropping m after dropping n is dropping n + m, reversed to rewrite toward the simple side.
law drop_drop_sym:
  for -a: Quant
  for -A: Kind(a)
  for xs: List<a, A>
  for n: Nat
  for -m: Nat
  {List.drop(a, A, xs, Nat.add(n, m)) == List.drop(a, A, List.drop(a, A, xs, n), m) : List<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.drop
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.add
  https://jend.leeeet.dev/definition.txt?path=bend-mathlib@0.8.1.0/list.bend&name=drop_drop