def w64.first_set_none
import bend-osdev-algo@0.1.0.0/PROOF.bend as PROOFimport Base
import bend-osdev-word64@0.1.0.0/word64.bend as W
import bend-osdev-algo@0.1.0.0/algo.bend as A
733def w64.first_set_none(+a: W.W64, e: {A.bits64.first_set(a) == None{} : Maybe<&2, Nat>}) -> {a == W.W64.zero() : W.W64}:
734 w64.zero(a, bitw.first_set_none(64n, A.bits64.word(a), e))