def byte_xor_byte

bend-osdev-legacy-ciphers@0.1.0.0 · PROOF.bend:145

import Base
import bend-osdev-bytes@0.1.0.0/bytes.bend as B

145# the low byte of a XOR depends only on the low bytes
146def byte_xor_byte(z: U32, k: U32) -> {B.byte(U32.xor(z, k)) == B.byte(U32.xor(B.byte(z), k)) : U32}:
147  match z k:
148    case U32{WCon{a0, WCon{a1, WCon{a2, WCon{a3, WCon{a4, WCon{a5, WCon{a6, WCon{a7, WCon{a8, WCon{a9, WCon{a10, WCon{a11, WCon{a12, WCon{a13, WCon{a14, WCon{a15, WCon{a16, WCon{a17, WCon{a18, WCon{a19, WCon{a20, WCon{a21, WCon{a22, WCon{a23, WCon{a24, WCon{a25, WCon{a26, WCon{a27, WCon{a28, WCon{a29, WCon{a30, WCon{a31, WNil{}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}} U32{WCon{b0, WCon{b1, WCon{b2, WCon{b3, WCon{b4, WCon{b5, WCon{b6, WCon{b7, WCon{b8, WCon{b9, WCon{b10, WCon{b11, WCon{b12, WCon{b13, WCon{b14, WCon{b15, WCon{b16, WCon{b17, WCon{b18, WCon{b19, WCon{b20, WCon{b21, WCon{b22, WCon{b23, WCon{b24, WCon{b25, WCon{b26, WCon{b27, WCon{b28, WCon{b29, WCon{b30, WCon{b31, WNil{}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}:
149      {==}