PROOF.rr_back: def of bend-osdev-bytes@0.1.1.1
Import: import bend-osdev-bytes@0.1.1.1/PROOF.bend as PROOF
Lines 515-517 of bend-osdev-bytes@0.1.1.1/PROOF.bend: https://jend.leeeet.dev/read.txt?path=bend-osdev-bytes@0.1.1.1/PROOF.bend&start_line=515&end_line=517

import Base
import bend-osdev-bytes@0.1.1.1/bytes.bend as B

# a structural list, reversed onto Nil and back, is itself
def rr_back(+zs: List<&2, U32>) -> {B.rev_onto(B.rev_onto(zs, Nil{}), Nil{}) == zs : List<&2, U32>}:
  Equal.trans(List<&2, U32>, B.rev_onto(B.rev_onto(zs, Nil{}), Nil{}), List.append(&2, U32, zs, Nil{}), zs, ru_rr(zs, Nil{}, Nil{}), app_nilu(zs))

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.trans
  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=U32
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-bytes@0.1.1.1/PROOF.bend&name=app_nilu
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-bytes@0.1.1.1/PROOF.bend&name=ru_rr
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-bytes@0.1.1.1/bytes.bend&name=rev_onto