def o_c

bend-collections-laws-crypto@1.0.0.0 · proofs/crypto/curve25519/freeze.bend:104

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/nat.bend as N
import bend-collections-laws-crypto@1.0.0.0/proofs/lib/logic.bend as L
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/crypto/curve25519/num.bend as M
import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/limbs.bend as LM
import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/poly.bend as PL
import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/reduce.bend as RD
import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/consts.bend as K

104# case c >= 1: c == 1 and value(s) + p == value(x)
105def o_c(+one: Nat, +h1: {one == 1n : Nat}, +pp: Nat, +hP: {Nat.add(1n+pp, 19n) == WD.sc(255n, one) : Nat}, +x: List<&2, U32>, +cp: List<&2, U32>, +hx: {LM.okb(32n, x, 255n) == True{} : Bool}, +hk: {LM.okb(32n, cp, 128n) == True{} : Bool}, +hv: {K.valo(one, cp) == Nat.add(1n+pp, 38n) : Nat}, +hc: {Nat.is_lt(v(LM.cc(F.carry(F.addl(x, cp), 0))), one) == False{} : Bool}) -> {v(LM.cc(F.carry(F.addl(x, cp), 0))) == one : Nat}:
106  +P = {1n+pp : Nat}
107  +r = F.carry(F.addl(x, cp), 0)
108  +c = v(LM.cc(r))
109  +vs = FS.value(LM.cl(r))
110  +T = LM.shn(32n, one)
111  +ev = cs_val(one, h1, pp, x, cp, hx, hk, hv)
112  +a = N.le_trans(LM.shn(32n, c), Nat.add(vs, LM.shn(32n, c)), Nat.add(FS.value(x), Nat.add(P, 38n)), PL.le_add_l(vs, LM.shn(32n, c)), N.eq_le(Nat.add(vs, LM.shn(32n, c)), Nat.add(FS.value(x), Nat.add(P, 38n)), ev))
113  +tv = t_val(one, h1, pp, hP)
114  +k1 = L.subst(Nat, z => {Nat.is_le(Nat.add(P, 38n), z) == True{} : Bool}, Nat.add(Nat.add(P, P), 38n), T, Equal.sym(Nat, T, Nat.add(Nat.add(P, P), 38n), tv), M.le_add_r(P, Nat.add(P, P), 38n, N.le_add_right(P, P)))
115  +b = N.lt_le_trans(Nat.add(FS.value(x), Nat.add(P, 38n)), Nat.add(T, Nat.add(P, 38n)), Nat.add(T, T), N.lt_add_r2(FS.value(x), T, Nat.add(P, 38n), RD.val_lt(one, h1, 32n, x, hx)), N.le_add_left(Nat.add(P, 38n), T, T, k1))
116  +d = N.le_lt_trans(LM.shn(32n, c), Nat.add(FS.value(x), Nat.add(P, 38n)), Nat.add(T, T), a, b)
117  +d2 = L.subst(Nat, z => {Nat.is_lt(LM.shn(32n, c), z) == True{} : Bool}, Nat.add(T, T), LM.shn(32n, Nat.add(one, one)), M.sc_add(256n, one, one), d)
118  +c2 = RD.shn_lt_cancel(c, Nat.add(one, one), d2)
119  +c2b = L.subst(Nat, o => {Nat.is_lt(c, Nat.add(o, o)) == True{} : Bool}, one, 1n, h1, c2)
120  +cle = L.subst(Nat, o => {Nat.is_le(c, o) == True{} : Bool}, 1n, one, Equal.sym(Nat, one, 1n, h1), N.lt_succ_le(c, 1n, c2b))
121  N.le_antisym(c, one, cle, N.not_lt_le(c, one, hc))