def set.sub_intro

bend-osdev-caps@0.1.0.0 · PROOF.bend:143

import Base
import bend-osdev-caps@0.1.0.0/caps.bend as C

143# a set within another, from its parts within theirs, and back
144def set.sub_intro(+al: Word(32n), +bl: Word(32n), +ah: Word(9n), +bh: Word(9n)) -> {C.CapBits.subset(32n, al, bl) == True{} : Bool} -> {C.CapBits.subset(9n, ah, bh) == True{} : Bool} -> {C.CapSet.subset(C.CapSetW{U32{al}, ah}, C.CapSetW{U32{bl}, bh}) == True{} : Bool}:
145  hl => hh =>
146    %Equal.sym(Bool, Cmp.is_eq(Word.cmp(32n, Word.and(32n, al, Word.not(32n, bl)), Word.zero(32n))), C.CapBits.subset(32n, al, bl), set.bridge(32n, al, bl)) : {Bool.and(_, C.CapBits.subset(9n, ah, bh)) == True{} : Bool}
147    bool.and2(C.CapBits.subset(32n, al, bl), C.CapBits.subset(9n, ah, bh))(hl)(hh)