def freeze_val

bend-collections-laws-crypto@1.0.0.0 · proofs/crypto/curve25519/canon.bend:94

import Base
import bend-collections-laws-crypto@1.0.0.0/spec/crypto/curve25519/field.bend as FS
import bend-collections-laws-crypto@1.0.0.0/src/crypto/curve25519/field.bend as F
import bend-collections-laws-crypto@1.0.0.0/proofs/lib/word.bend as WD
import bend-collections-laws-crypto@1.0.0.0/proofs/math/natural/arith.bend as NR
import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/limbs.bend as LM

94# value(freeze(x)) == value(x) mod p
95def freeze_val(+one: Nat, +h1: {one == 1n : Nat}, +pp: Nat, +hP: {Nat.add(1n+pp, 19n) == WD.sc(255n, one) : Nat}, +x: List<&2, U32>, +hx: {LM.okb(32n, x, 255n) == True{} : Bool}) -> {FS.value(F.freeze(x)) == Nat.mod(FS.value(x), 1n+pp) : Nat}:
96  +r = FS.value(F.freeze(x))
97  +e1 = Equal.sym(Nat, Nat.mod(r, 1n+pp), r, NR.mod_of(0n, pp, r, freeze_lt(one, h1, pp, hP, x, hx)))
98  Equal.trans(Nat, r, Nat.mod(r, 1n+pp), Nat.mod(FS.value(x), 1n+pp), e1, freeze_ceq(one, h1, pp, hP, x, hx))