PROOF.pk.wself: def of bend-osdev-pkcs7@0.1.0.0
Import: import bend-osdev-pkcs7@0.1.0.0/PROOF.bend as PROOF
Lines 210-226 of bend-osdev-pkcs7@0.1.0.0/PROOF.bend: https://jend.leeeet.dev/read.txt?path=bend-osdev-pkcs7@0.1.0.0/PROOF.bend&start_line=210&end_line=226

import Base

# a word XOR itself is zero, bit by bit
def pk.wself(+n: Nat, w: Word(n)) -> {Word.xor(n, w, w) == Word.zero(n) : Word(n)}:
  match n:
    case 0n:
      match w:
        case WNil{}:
          {==}
    case 1n+p:
      match w:
        case WCon{h, t}:
          match h:
            case False{}:
              %pk.wself(p, t) : {WCon{False{}, Word.xor(p, t, t)} == WCon{False{}, _} : Word(1n+p)}
              {==}
            case True{}:
              %pk.wself(p, t) : {WCon{False{}, Word.xor(p, t, t)} == WCon{False{}, _} : Word(1n+p)}
              {==}

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Word
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Word.Con
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Word.Nil
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Word.xor
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Word.zero