def xk
import bend-osdev-gf@0.1.1.0/PROOF.bend as PROOFimport Base
import bend-osdev-gf@0.1.1.0/gf.bend as G
530def xk(n: Nat, b: G.Gf8Bits, +p: G.Gf8Bits) -> G.Gf8Bits:
531 match n:
532 case 0n:
533 b
534 case 1n+k:
535 xk(k, G.Gf8Bits.x(b, p), p)