proofs/math/random/fround.bend

bend-collections-laws-math@1.0.0.0 · 378 lines · 44 definitions

1import Base
2import bend-collections-laws-math@1.0.0.0/spec/lib/common.bend as C
3import bend-collections-laws-math@1.0.0.0/spec/math/f64.bend as SF
4import bend-collections-laws-math@1.0.0.0/spec/math/w64.bend as SW
5import bend-collections-laws-math@1.0.0.0/src/math/f64.bend as F
6import bend-collections-laws-math@1.0.0.0/src/math/w64.bend as X
7import bend-collections-laws-math@1.0.0.0/src/math/u64.bend as WU
8import bend-collections-laws-math@1.0.0.0/proofs/lib/nat.bend as N
9import bend-collections-laws-math@1.0.0.0/proofs/lib/logic.bend as L
10import bend-collections-laws-math@1.0.0.0/proofs/lib/lemmas/proofs/nat_algebra.bend as NA
11import bend-collections-laws-math@1.0.0.0/proofs/math/typed/width.bend as WW
12import bend-collections-laws-math@1.0.0.0/proofs/math/typed/u32laws.bend as LW
13import bend-collections-laws-math@1.0.0.0/proofs/math/typed/w64add.bend as WA
14import bend-collections-laws-math@1.0.0.0/proofs/math/typed/f64bits.bend as FB
15import bend-collections-laws-math@1.0.0.0/proofs/math/typed/natcmp.bend as NC
16import bend-collections-laws-math@1.0.0.0/proofs/math/typed/w64sh.bend as SH
17import bend-collections-laws-math@1.0.0.0/proofs/lib/u32.bend as U
18import bend-collections-laws-math@1.0.0.0/proofs/lib/u32half.bend as UH
19import bend-collections-laws-math@1.0.0.0/proofs/lib/u32alg.bend as A
20import bend-collections-laws-math@1.0.0.0/proofs/lib/word.bend as WD
21import bend-collections-laws-math@1.0.0.0/proofs/lib/lemmas/spec/numeric.bend as S
22import bend-collections-laws-math@1.0.0.0/src/math/natural.bend as M
23import bend-collections-laws-math@1.0.0.0/proofs/math/natural/bits.bend as BT
24import bend-collections-laws-math@1.0.0.0/proofs/math/typed/f64bl.bend as FO
25
26# Copied from proofs/math/typed/f64round.bend and f64rtools.bend: only the
27# lemmas proofs/math/random/float.bend needs (and their dependencies), so the
28# random proofs do not re-check the heavy rounding lemmas (rj2, rp_nc, ...).
29
30def bits(+s: Bool, +n: Nat) -> F.F64:
31  F.Bits{U32.from_nat(C.low(32n, n)), U32.from_nat(Nat.add(C.high(32n, n), C.shift(31n, SF.b2n(s))))}
32
33def enc_bits(+s: Bool, +ef: Nat, +f: Nat) -> {SF.encode(s, ef, f) == bits(s, Nat.add(f, C.shift(52n, ef))) : F.F64}:
34  +t = C.shift(20n, ef)
35  +n = Nat.add(f, C.shift(52n, ef))
36  +b = C.shift(31n, SF.b2n(s))
37  +e52 = WW.shift_comp(32n, 20n, ef)
38  +el = Equal.trans(Nat, C.low(32n, n), C.low(32n, Nat.add(f, C.shift(32n, t))), C.low(32n, f), Equal.cong(Nat, Nat, z => C.low(32n, Nat.add(f, z)), C.shift(52n, ef), C.shift(32n, t), e52), WW.low_add_shift(32n, f, t))
39  +eh0 = Equal.trans(Nat, C.high(32n, n), C.high(32n, Nat.add(f, C.shift(32n, t))), Nat.add(C.high(32n, f), t), Equal.cong(Nat, Nat, z => C.high(32n, Nat.add(f, z)), C.shift(52n, ef), C.shift(32n, t), e52), WW.high_add_shift(32n, f, t))
40  +eh = Equal.trans(Nat, Nat.add(C.high(32n, n), b), Nat.add(Nat.add(C.high(32n, f), t), b), Nat.add(C.high(32n, f), C.shift(20n, Nat.add(ef, C.shift(11n, SF.b2n(s))))), Equal.cong(Nat, Nat, z => Nat.add(z, b), C.high(32n, n), Nat.add(C.high(32n, f), t), eh0), FB.fold(C.high(32n, f), ef, SF.b2n(s)))
41  +e = Equal.trans(F.F64, bits(s, n), F.Bits{U32.from_nat(C.low(32n, f)), U32.from_nat(Nat.add(C.high(32n, n), b))}, SF.encode(s, ef, f), Equal.cong(Nat, F.F64, z => F.Bits{U32.from_nat(z), U32.from_nat(Nat.add(C.high(32n, n), b))}, C.low(32n, n), C.low(32n, f), el), Equal.cong(Nat, F.F64, z => F.Bits{U32.from_nat(C.low(32n, f)), U32.from_nat(z)}, Nat.add(C.high(32n, n), b), Nat.add(C.high(32n, f), C.shift(20n, Nat.add(ef, C.shift(11n, SF.b2n(s))))), eh))
42  Equal.sym(F.F64, bits(s, n), SF.encode(s, ef, f), e)
43
44def rne_c(+q: Nat, +c: Cmp) -> Nat:
45  Nat.add(q, SF.b2n(Bool.or(Cmp.is_lt(SF.flip(c)), Bool.and(Cmp.is_eq(c), Nat.is_eq(Nat.mod(q, 2n), 1n)))))
46
47def rne_cmp(+q: Nat, +r: Nat, +h: Nat) -> {SF.rne_up(q, r, h) == rne_c(q, Nat.cmp(r, h)) : Nat}:
48  Equal.cong(Cmp, Nat, t => Nat.add(q, SF.b2n(Bool.or(Cmp.is_lt(t), Bool.and(Cmp.is_eq(Nat.cmp(r, h)), Nat.is_eq(Nat.mod(q, 2n), 1n))))), Nat.cmp(h, r), SF.flip(Nat.cmp(r, h)), Equal.sym(Cmp, SF.flip(Nat.cmp(r, h)), Nat.cmp(h, r), NC.cmp_flip(r, h)))
49
50def fz(+d: Nat) -> {C.fits(d, 0n) == True{} : Bool}:
51  match d:
52    case 0n:
53      {==}
54    case 1n+ +p:
55      fz(p)
56
57def fits_add1(+k: Nat, +a: Nat, +b: Nat, +ha: {C.fits(k, a) == True{} : Bool}, +hb: {C.fits(k, b) == True{} : Bool}) -> {C.fits(1n+k, Nat.add(a, b)) == True{} : Bool}:
58  +P = C.pow2(k)
59  +h1 = N.lt_add_r2(a, P, b, WW.lt_of_fits(k, a, ha))
60  +h2 = N.lt_add_left(b, P, P, WW.lt_of_fits(k, b, hb))
61  +h3 = N.lt_trans(Nat.add(a, b), Nat.add(P, b), Nat.add(P, P), h1, h2)
62  +h4 = L.subst(Nat, z => {Nat.is_lt(Nat.add(a, b), z) == True{} : Bool}, Nat.add(P, P), Nat.double(P), Equal.sym(Nat, Nat.double(P), Nat.add(P, P), NA.double_self(P)), h3)
63  WW.fits_of_lt(1n+k, Nat.add(a, b), h4)
64
65def sub_add_r(+a: Nat, +b: Nat, +m: Nat, +h: {Nat.is_le(m, a) == True{} : Bool}) -> {Nat.sub(Nat.add(a, b), m) == Nat.add(Nat.sub(a, m), b) : Nat}:
66  +d = Nat.sub(a, m)
67  Equal.trans(Nat, Nat.sub(Nat.add(a, b), m), Nat.sub(Nat.add(Nat.add(m, d), b), m), Nat.add(d, b), Equal.cong(Nat, Nat, z => Nat.sub(Nat.add(z, b), m), a, Nat.add(m, d), Equal.sym(Nat, Nat.add(m, d), a, N.sub_add(a, m, h))), Equal.trans(Nat, Nat.sub(Nat.add(Nat.add(m, d), b), m), Nat.sub(Nat.add(m, Nat.add(d, b)), m), Nat.add(d, b), Equal.cong(Nat, Nat, z => Nat.sub(z, m), Nat.add(Nat.add(m, d), b), Nat.add(m, Nat.add(d, b)), NA.add_assoc(m, d, b)), N.add_sub_cancel(m, Nat.add(d, b))))
68
69def parq(+q: Nat) -> {Nat.add(q, SF.b2n(Nat.is_eq(C.bit(q), 1n))) == Nat.double(C.half(Nat.add(q, 1n))) : Nat}:
70  match q:
71    case 0n:
72      {==}
73    case 1n:
74      {==}
75    case 2n+ +p:
76      Equal.cong(Nat, Nat, z => 2n+z, Nat.add(p, SF.b2n(Nat.is_eq(C.bit(p), 1n))), Nat.double(C.half(Nat.add(p, 1n))), parq(p))
77
78def subm(+n: Nat) -> {Nat.sub(n, Nat.mod(n, 2n)) == Nat.double(C.half(n)) : Nat}:
79  Equal.trans(Nat, Nat.sub(n, Nat.mod(n, 2n)), Nat.sub(n, C.bit(n)), Nat.double(C.half(n)), Equal.cong(Nat, Nat, z => Nat.sub(n, z), Nat.mod(n, 2n), C.bit(n), Equal.sym(Nat, C.bit(n), Nat.mod(n, 2n), WW.bit_mod(n))), Equal.trans(Nat, Nat.sub(n, C.bit(n)), Nat.sub(Nat.add(C.bit(n), Nat.double(C.half(n))), C.bit(n)), Nat.double(C.half(n)), Equal.cong(Nat, Nat, z => Nat.sub(z, C.bit(n)), n, Nat.add(C.bit(n), Nat.double(C.half(n))), WW.hb(n)), N.add_sub_cancel(C.bit(n), Nat.double(C.half(n)))))
80
81def rp_c(+q0: Nat, +r0: Nat, +hr: {C.fits(10n, r0) == True{} : Bool}, +c: Cmp, +hc: {Nat.cmp(r0, 512n) == c : Cmp}) -> {SF.pick(Nat, Nat.is_eq(r0, 512n), Nat.sub(Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), Nat.mod(Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), 2n)), Nat.add(q0, C.high(10n, Nat.add(r0, 512n)))) == SF.rne_up(q0, r0, 512n) : Nat}:
82  match c:
83    case LT{}:
84      +hlt = NC.lt_of_cmp(r0, 512n, hc)
85      +he = Equal.cong(Cmp, Bool, t => Cmp.is_eq(t), Nat.cmp(r0, 512n), LT{}, hc)
86      +hg = Equal.cong(Cmp, Bool, t => Cmp.is_lt(t), Nat.cmp(512n, r0), GT{}, Equal.trans(Cmp, Nat.cmp(512n, r0), SF.flip(Nat.cmp(r0, 512n)), GT{}, Equal.sym(Cmp, SF.flip(Nat.cmp(r0, 512n)), Nat.cmp(512n, r0), NC.cmp_flip(r0, 512n)), Equal.cong(Cmp, Cmp, t => SF.flip(t), Nat.cmp(r0, 512n), LT{}, hc)))
87      +f = WW.fits_of_lt(10n, Nat.add(r0, 512n), N.lt_add_r2(r0, 512n, 512n, hlt))
88      +h0 = N.eq_from_is_eq(C.high(10n, Nat.add(r0, 512n)), 0n, f)
89      +l1 = Equal.cong(Bool, Nat, t => SF.pick(Nat, t, Nat.sub(Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), Nat.mod(Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), 2n)), Nat.add(q0, C.high(10n, Nat.add(r0, 512n)))), Nat.is_eq(r0, 512n), False{}, he)
90      +l2 = Equal.cong(Nat, Nat, z => Nat.add(q0, z), C.high(10n, Nat.add(r0, 512n)), 0n, h0)
91      +r1 = Equal.cong(Bool, Nat, t => Nat.add(q0, SF.b2n(Bool.or(t, Bool.and(Nat.is_eq(r0, 512n), Nat.is_eq(Nat.mod(q0, 2n), 1n))))), Nat.is_lt(512n, r0), False{}, hg)
92      +r2 = Equal.cong(Bool, Nat, t => Nat.add(q0, SF.b2n(Bool.or(False{}, Bool.and(t, Nat.is_eq(Nat.mod(q0, 2n), 1n))))), Nat.is_eq(r0, 512n), False{}, he)
93      Equal.trans(Nat, SF.pick(Nat, Nat.is_eq(r0, 512n), Nat.sub(Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), Nat.mod(Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), 2n)), Nat.add(q0, C.high(10n, Nat.add(r0, 512n)))), Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), SF.rne_up(q0, r0, 512n), l1, Equal.trans(Nat, Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), Nat.add(q0, 0n), SF.rne_up(q0, r0, 512n), l2, Equal.sym(Nat, SF.rne_up(q0, r0, 512n), Nat.add(q0, 0n), Equal.trans(Nat, SF.rne_up(q0, r0, 512n), Nat.add(q0, SF.b2n(Bool.or(False{}, Bool.and(Nat.is_eq(r0, 512n), Nat.is_eq(Nat.mod(q0, 2n), 1n))))), Nat.add(q0, 0n), r1, r2))))
94    case GT{}:
95      +hgt = NC.lt_of_gt(r0, 512n, hc)
96      +he = Equal.cong(Cmp, Bool, t => Cmp.is_eq(t), Nat.cmp(r0, 512n), GT{}, hc)
97      +d = Nat.sub(r0, 512n)
98      +ed = N.sub_add(r0, 512n, N.lt_le(512n, r0, hgt))
99      +ex = Equal.trans(Nat, Nat.add(r0, 512n), Nat.add(Nat.add(512n, d), 512n), Nat.add(d, C.shift(10n, 1n)), Equal.cong(Nat, Nat, z => Nat.add(z, 512n), r0, Nat.add(512n, d), Equal.sym(Nat, Nat.add(512n, d), r0, ed)), Equal.trans(Nat, Nat.add(Nat.add(512n, d), 512n), Nat.add(512n, Nat.add(d, 512n)), Nat.add(d, C.shift(10n, 1n)), NA.add_assoc(512n, d, 512n), Equal.trans(Nat, Nat.add(512n, Nat.add(d, 512n)), Nat.add(1024n, d), Nat.add(d, C.shift(10n, 1n)), Equal.cong(Nat, Nat, z => Nat.add(512n, z), Nat.add(d, 512n), Nat.add(512n, d), NA.add_comm(d, 512n)), NA.add_comm(1024n, d))))
100      +hd = SH.fits_lek(10n, d, r0, UH.sub_le(r0, 512n), hr)
101      +h1 = Equal.trans(Nat, C.high(10n, Nat.add(r0, 512n)), C.high(10n, Nat.add(d, C.shift(10n, 1n))), 1n, Equal.cong(Nat, Nat, z => C.high(10n, z), Nat.add(r0, 512n), Nat.add(d, C.shift(10n, 1n)), ex), WW.high_u(10n, d, 1n, hd))
102      +l1 = Equal.cong(Bool, Nat, t => SF.pick(Nat, t, Nat.sub(Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), Nat.mod(Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), 2n)), Nat.add(q0, C.high(10n, Nat.add(r0, 512n)))), Nat.is_eq(r0, 512n), False{}, he)
103      +l2 = Equal.cong(Nat, Nat, z => Nat.add(q0, z), C.high(10n, Nat.add(r0, 512n)), 1n, h1)
104      +r1 = Equal.cong(Bool, Nat, t => Nat.add(q0, SF.b2n(Bool.or(t, Bool.and(Nat.is_eq(r0, 512n), Nat.is_eq(Nat.mod(q0, 2n), 1n))))), Nat.is_lt(512n, r0), True{}, hgt)
105      Equal.trans(Nat, SF.pick(Nat, Nat.is_eq(r0, 512n), Nat.sub(Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), Nat.mod(Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), 2n)), Nat.add(q0, C.high(10n, Nat.add(r0, 512n)))), Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), SF.rne_up(q0, r0, 512n), l1, Equal.trans(Nat, Nat.add(q0, C.high(10n, Nat.add(r0, 512n))), Nat.add(q0, 1n), SF.rne_up(q0, r0, 512n), l2, Equal.sym(Nat, SF.rne_up(q0, r0, 512n), Nat.add(q0, 1n), r1)))
106    case EQ{}:
107      +er = NC.eq_of_cmp(r0, 512n, hc)
108      +b1 = subm(Nat.add(q0, 1n))
109      +b2 = Equal.trans(Nat, Nat.add(q0, SF.b2n(Nat.is_eq(Nat.mod(q0, 2n), 1n))), Nat.add(q0, SF.b2n(Nat.is_eq(C.bit(q0), 1n))), Nat.double(C.half(Nat.add(q0, 1n))), Equal.cong(Nat, Nat, z => Nat.add(q0, SF.b2n(Nat.is_eq(z, 1n))), Nat.mod(q0, 2n), C.bit(q0), Equal.sym(Nat, C.bit(q0), Nat.mod(q0, 2n), WW.bit_mod(q0))), parq(q0))
110      +base = Equal.trans(Nat, Nat.sub(Nat.add(q0, 1n), Nat.mod(Nat.add(q0, 1n), 2n)), Nat.double(C.half(Nat.add(q0, 1n))), Nat.add(q0, SF.b2n(Nat.is_eq(Nat.mod(q0, 2n), 1n))), b1, Equal.sym(Nat, Nat.add(q0, SF.b2n(Nat.is_eq(Nat.mod(q0, 2n), 1n))), Nat.double(C.half(Nat.add(q0, 1n))), b2))
111      L.subst(Nat, z => {SF.pick(Nat, Nat.is_eq(z, 512n), Nat.sub(Nat.add(q0, C.high(10n, Nat.add(z, 512n))), Nat.mod(Nat.add(q0, C.high(10n, Nat.add(z, 512n))), 2n)), Nat.add(q0, C.high(10n, Nat.add(z, 512n)))) == SF.rne_up(q0, z, 512n) : Nat}, 512n, r0, Equal.sym(Nat, r0, 512n, er), base)
112
113def bl_gt(+k: Nat, +n: Nat, +h1: {C.fits(k, n) == False{} : Bool}, +h2: {C.fits(1n+k, n) == True{} : Bool}, +hg: {Nat.is_le(C.pow2(2n+k), C.pow2(M.bit_length(n))) == True{} : Bool}) -> {M.bit_length(n) == 1n+k : Nat}:
114  match n:
115    case 0n:
116      NC.absurd_tf({M.bit_length(0n) == 1n+k : Nat}, Equal.trans(Bool, False{}, C.fits(k, 0n), True{}, Equal.sym(Bool, C.fits(k, 0n), False{}, h1), fz(k)))
117    case 1n+ +np:
118      +P = C.pow2(2n+k)
119      +hd = N.double_lt(1n+np, C.pow2(1n+k), WW.lt_of_fits(1n+k, 1n+np, h2))
120      +hle = N.le_trans(P, C.pow2(M.bit_length(1n+np)), Nat.double(1n+np), hg, BT.bit_length_le(np))
121      NC.absurd_tf({M.bit_length(1n+np) == 1n+k : Nat}, Equal.trans(Bool, False{}, Nat.is_lt(P, P), True{}, Equal.sym(Bool, Nat.is_lt(P, P), False{}, N.lt_irrefl(P)), N.le_lt_trans(P, Nat.double(1n+np), P, hle, hd)))
122
123def bl_c(+k: Nat, +n: Nat, +h1: {C.fits(k, n) == False{} : Bool}, +h2: {C.fits(1n+k, n) == True{} : Bool}, +c: Cmp, +hc: {Nat.cmp(M.bit_length(n), 1n+k) == c : Cmp}) -> {M.bit_length(n) == 1n+k : Nat}:
124  match c:
125    case EQ{}:
126      NC.eq_of_cmp(M.bit_length(n), 1n+k, hc)
127    case LT{}:
128      +hl = N.lt_succ_le(M.bit_length(n), k, NC.lt_of_cmp(M.bit_length(n), 1n+k, hc))
129      +hn = N.lt_le_trans(n, C.pow2(M.bit_length(n)), C.pow2(k), BT.bit_length_lt(n), N.pow2_mono(M.bit_length(n), k, hl))
130      NC.absurd_tf({M.bit_length(n) == 1n+k : Nat}, Equal.trans(Bool, False{}, C.fits(k, n), True{}, Equal.sym(Bool, C.fits(k, n), False{}, h1), WW.fits_of_lt(k, n, hn)))
131    case GT{}:
132      +hg = N.pow2_mono(2n+k, M.bit_length(n), N.lt_succ_le_succ(1n+k, M.bit_length(n), NC.lt_of_gt(M.bit_length(n), 1n+k, hc)))
133      bl_gt(k, n, h1, h2, hg)
134
135def fits_hc(+a: Nat, +b: Nat, +n: Nat) -> {C.fits(Nat.add(a, b), n) == C.fits(b, C.high(a, n)) : Bool}:
136  Equal.cong(Nat, Bool, z => Nat.is_eq(z, 0n), C.high(Nat.add(a, b), n), C.high(b, C.high(a, n)), WW.high_comp(b, a, n))
137
138def succ_le(+a: Nat, +b: Nat, +h: {Nat.is_lt(a, b) == True{} : Bool}) -> {Nat.is_le(Nat.add(a, 1n), b) == True{} : Bool}:
139  L.subst(Nat, z => {Nat.is_le(z, b) == True{} : Bool}, 1n+a, Nat.add(a, 1n), Equal.sym(Nat, Nat.add(a, 1n), 1n+a, Equal.trans(Nat, Nat.add(a, 1n), Nat.add(1n, a), 1n+a, NA.add_comm(a, 1n), {==})), N.lt_succ_le_succ(a, b, h))
140
141def nfit_c(+k: Nat, +a: Nat, +r: Nat, +hle: {Nat.is_le(a, r) == True{} : Bool}, +f: {C.fits(k, a) == False{} : Bool}, +b: Bool, +hb: {C.fits(k, r) == b : Bool}) -> {b == False{} : Bool}:
142  match b:
143    case True{}:
144      NC.absurd_tf({True{} == False{} : Bool}, Equal.trans(Bool, False{}, C.fits(k, a), True{}, Equal.sym(Bool, C.fits(k, a), False{}, f), SH.fits_lek(k, a, r, hle, hb)))
145    case False{}:
146      {==}
147
148def nfit(+k: Nat, +a: Nat, +r: Nat, +hle: {Nat.is_le(a, r) == True{} : Bool}, +f: {C.fits(k, a) == False{} : Bool}) -> {C.fits(k, r) == False{} : Bool}:
149  nfit_c(k, a, r, hle, f, C.fits(k, r), {==})
150
151def lt_fit(+k: Nat, +one: Nat, +h1: {one == 1n : Nat}, +n: Nat) -> {Nat.is_lt(n, C.shift(k, one)) == C.fits(k, n) : Bool}:
152  +e2a = Equal.trans(Bool, Nat.is_lt(n, C.shift(k, 1n)), Nat.is_lt(n, C.pow2(k)), C.fits(k, n), Equal.cong(Nat, Bool, z => Nat.is_lt(n, z), C.shift(k, 1n), C.pow2(k), WW.shift_one(k)), Equal.sym(Bool, C.fits(k, n), Nat.is_lt(n, C.pow2(k)), WW.fits_lt(k, n)))
153  L.subst(Nat, o => {Nat.is_lt(n, C.shift(k, o)) == C.fits(k, n) : Bool}, 1n, one, Equal.sym(Nat, one, 1n, h1), e2a)
154
155def efv(+u: Nat, +EF: Nat, +hu: {Nat.add(EF, 1926n) == u : Nat}) -> {Nat.sub(Nat.add(u, 1075n), SF.zb()) == 1n+EF : Nat}:
156  +e1 = Equal.cong(Nat, Nat, z => Nat.sub(Nat.add(z, 1075n), SF.zb()), u, Nat.add(EF, 1926n), Equal.sym(Nat, Nat.add(EF, 1926n), u, hu))
157  +e2 = Equal.cong(Nat, Nat, z => Nat.sub(z, SF.zb()), Nat.add(Nat.add(EF, 1926n), 1075n), Nat.add(EF, 3001n), NA.add_assoc(EF, 1926n, 1075n))
158  +e3 = Equal.cong(Nat, Nat, z => Nat.sub(z, SF.zb()), Nat.add(EF, 3001n), Nat.add(3001n, EF), NA.add_comm(EF, 3001n))
159  Equal.trans(Nat, Nat.sub(Nat.add(u, 1075n), SF.zb()), Nat.sub(Nat.add(Nat.add(EF, 1926n), 1075n), SF.zb()), 1n+EF, e1, Equal.trans(Nat, Nat.sub(Nat.add(Nat.add(EF, 1926n), 1075n), SF.zb()), Nat.sub(Nat.add(EF, 3001n), SF.zb()), 1n+EF, e2, e3))
160
161def ef2v(+u: Nat, +EF: Nat, +hu: {Nat.add(EF, 1926n) == u : Nat}) -> {Nat.sub(Nat.add(1n+u, 1075n), SF.zb()) == 2n+EF : Nat}:
162  +e1 = Equal.cong(Nat, Nat, z => Nat.sub(Nat.add(1n+z, 1075n), SF.zb()), u, Nat.add(EF, 1926n), Equal.sym(Nat, Nat.add(EF, 1926n), u, hu))
163  +e2 = Equal.cong(Nat, Nat, z => Nat.sub(z, SF.zb()), Nat.add(Nat.add(1n+EF, 1926n), 1075n), Nat.add(1n+EF, 3001n), NA.add_assoc(1n+EF, 1926n, 1075n))
164  +e3 = Equal.cong(Nat, Nat, z => Nat.sub(z, SF.zb()), Nat.add(1n+EF, 3001n), Nat.add(3001n, 1n+EF), NA.add_comm(1n+EF, 3001n))
165  Equal.trans(Nat, Nat.sub(Nat.add(1n+u, 1075n), SF.zb()), Nat.sub(Nat.add(Nat.add(1n+EF, 1926n), 1075n), SF.zb()), 2n+EF, e1, Equal.trans(Nat, Nat.sub(Nat.add(Nat.add(1n+EF, 1926n), 1075n), SF.zb()), Nat.sub(Nat.add(1n+EF, 3001n), SF.zb()), 2n+EF, e2, e3))
166
167def hi_one(+H0: Nat, +a: {Nat.is_eq(C.half(H0), 0n) == True{} : Bool}, +b: {Nat.is_eq(H0, 0n) == False{} : Bool}) -> {H0 == 1n : Nat}:
168  match H0:
169    case 0n:
170      Empty.absurd({0n == 1n : Nat}, LW.true_ne_false(b))
171    case 1n:
172      {==}
173    case 2n+ +p:
174      NC.absurd_tf({2n+p == 1n : Nat}, a)
175
176def f53h(+q: Nat) -> {C.fits(53n, q) == Nat.is_eq(C.half(C.high(52n, q)), 0n) : Bool}:
177  fits_hc(52n, 1n, q)
178
179def top_q(+one: Nat, +h1: {one == 1n : Nat}, +q: Nat, +hq: {Nat.is_le(q, C.shift(53n, one)) == True{} : Bool}, +hf: {C.fits(53n, q) == False{} : Bool}) -> {q == C.shift(52n, Nat.double(one)) : Nat}:
180  +hlt = Equal.trans(Bool, Nat.is_lt(q, C.shift(53n, one)), C.fits(53n, q), False{}, lt_fit(53n, one, h1, q), hf)
181  +hge = N.not_lt_le(q, C.shift(53n, one), hlt)
182  Equal.trans(Nat, q, C.shift(53n, one), C.shift(52n, Nat.double(one)), N.le_antisym(q, C.shift(53n, one), hq, hge), Equal.sym(Nat, C.shift(52n, Nat.double(one)), C.shift(53n, one), WW.shift_dbl(52n, one)))
183
184def pkg_c(+one: Nat, +h1: {one == 1n : Nat}, +s: Bool, +q: Nat, +u: Nat, +EF: Nat, +hEF: {Nat.add(EF, 1926n) == u : Nat}, +hq: {Nat.is_le(q, C.shift(53n, one)) == True{} : Bool}, +f53: Bool, +h53: {C.fits(53n, q) == f53 : Bool}, +f52: Bool, +h52: {C.fits(52n, q) == f52 : Bool}, +h0: {Bool.or(Bool.not(f52), Nat.is_eq(EF, 0n)) == True{} : Bool}, +hov: {Nat.is_lt(Nat.add(EF, SF.pick(Nat, f53, 1n, 2n)), 2047n) == True{} : Bool}) -> {SF.pick(F.F64, f53, SF.pick(F.F64, f52, SF.encode(s, 0n, q), SF.pack_e(s, Nat.sub(Nat.add(u, 1075n), SF.zb()), C.low(52n, q))), SF.pack_e(s, Nat.sub(Nat.add(1n+u, 1075n), SF.zb()), 0n)) == bits(s, Nat.add(q, C.shift(52n, EF))) : F.F64}:
185  match f53 f52:
186    case True{} True{}:
187      +e0 = N.eq_from_is_eq(EF, 0n, h0)
188      Equal.trans(F.F64, SF.encode(s, 0n, q), bits(s, Nat.add(q, C.shift(52n, 0n))), bits(s, Nat.add(q, C.shift(52n, EF))), enc_bits(s, 0n, q), Equal.cong(Nat, F.F64, z => bits(s, Nat.add(q, C.shift(52n, z))), 0n, EF, Equal.sym(Nat, EF, 0n, e0)))
189    case True{} False{}:
190      +eH = hi_one(C.high(52n, q), Equal.trans(Bool, Nat.is_eq(C.half(C.high(52n, q)), 0n), C.fits(53n, q), True{}, Equal.sym(Bool, C.fits(53n, q), Nat.is_eq(C.half(C.high(52n, q)), 0n), f53h(q)), h53), h52)
191      +e1 = efv(u, EF, hEF)
192      +eE = Equal.trans(Nat, Nat.sub(Nat.add(u, 1075n), SF.zb()), 1n+EF, Nat.add(C.high(52n, q), EF), e1, Equal.cong(Nat, Nat, z => Nat.add(z, EF), 1n, C.high(52n, q), Equal.sym(Nat, C.high(52n, q), 1n, eH)))
193      +hle = Equal.trans(Bool, Nat.is_le(2047n, Nat.sub(Nat.add(u, 1075n), SF.zb())), Nat.is_le(2047n, 1n+EF), False{}, Equal.cong(Nat, Bool, z => Nat.is_le(2047n, z), Nat.sub(Nat.add(u, 1075n), SF.zb()), 1n+EF, e1), Equal.trans(Bool, Nat.is_le(2047n, 1n+EF), Bool.not(Nat.is_lt(1n+EF, 2047n)), False{}, FB.le_nlt(2047n, 1n+EF), Equal.cong(Bool, Bool, t => Bool.not(t), Nat.is_lt(1n+EF, 2047n), True{}, L.subst(Nat, z => {Nat.is_lt(z, 2047n) == True{} : Bool}, Nat.add(EF, 1n), 1n+EF, Equal.trans(Nat, Nat.add(EF, 1n), Nat.add(1n, EF), 1n+EF, NA.add_comm(EF, 1n), {==}), hov))))
194      +p1 = Equal.cong(Bool, F.F64, t => SF.pick(F.F64, t, SF.inf(s), SF.encode(s, Nat.sub(Nat.add(u, 1075n), SF.zb()), C.low(52n, q))), Nat.is_le(2047n, Nat.sub(Nat.add(u, 1075n), SF.zb())), False{}, hle)
195      +p2 = enc_bits(s, Nat.sub(Nat.add(u, 1075n), SF.zb()), C.low(52n, q))
196      +v1 = Equal.trans(Nat, Nat.add(C.low(52n, q), C.shift(52n, Nat.sub(Nat.add(u, 1075n), SF.zb()))), Nat.add(C.low(52n, q), C.shift(52n, Nat.add(C.high(52n, q), EF))), Nat.add(q, C.shift(52n, EF)), Equal.cong(Nat, Nat, z => Nat.add(C.low(52n, q), C.shift(52n, z)), Nat.sub(Nat.add(u, 1075n), SF.zb()), Nat.add(C.high(52n, q), EF), eE), Equal.trans(Nat, Nat.add(C.low(52n, q), C.shift(52n, Nat.add(C.high(52n, q), EF))), Nat.add(C.low(52n, q), Nat.add(C.shift(52n, C.high(52n, q)), C.shift(52n, EF))), Nat.add(q, C.shift(52n, EF)), Equal.cong(Nat, Nat, z => Nat.add(C.low(52n, q), z), C.shift(52n, Nat.add(C.high(52n, q), EF)), Nat.add(C.shift(52n, C.high(52n, q)), C.shift(52n, EF)), WW.shift_add(52n, C.high(52n, q), EF)), Equal.trans(Nat, Nat.add(C.low(52n, q), Nat.add(C.shift(52n, C.high(52n, q)), C.shift(52n, EF))), Nat.add(Nat.add(C.low(52n, q), C.shift(52n, C.high(52n, q))), C.shift(52n, EF)), Nat.add(q, C.shift(52n, EF)), Equal.sym(Nat, Nat.add(Nat.add(C.low(52n, q), C.shift(52n, C.high(52n, q))), C.shift(52n, EF)), Nat.add(C.low(52n, q), Nat.add(C.shift(52n, C.high(52n, q)), C.shift(52n, EF))), NA.add_assoc(C.low(52n, q), C.shift(52n, C.high(52n, q)), C.shift(52n, EF))), Equal.cong(Nat, Nat, z => Nat.add(z, C.shift(52n, EF)), Nat.add(C.low(52n, q), C.shift(52n, C.high(52n, q))), q, Equal.sym(Nat, q, Nat.add(C.low(52n, q), C.shift(52n, C.high(52n, q))), WW.low_high(52n, q))))))
197      +p3 = Equal.cong(Nat, F.F64, z => bits(s, z), Nat.add(C.low(52n, q), C.shift(52n, Nat.sub(Nat.add(u, 1075n), SF.zb()))), Nat.add(q, C.shift(52n, EF)), v1)
198      Equal.trans(F.F64, SF.pack_e(s, Nat.sub(Nat.add(u, 1075n), SF.zb()), C.low(52n, q)), SF.encode(s, Nat.sub(Nat.add(u, 1075n), SF.zb()), C.low(52n, q)), bits(s, Nat.add(q, C.shift(52n, EF))), p1, Equal.trans(F.F64, SF.encode(s, Nat.sub(Nat.add(u, 1075n), SF.zb()), C.low(52n, q)), bits(s, Nat.add(C.low(52n, q), C.shift(52n, Nat.sub(Nat.add(u, 1075n), SF.zb())))), bits(s, Nat.add(q, C.shift(52n, EF))), p2, p3))
199    case False{} _:
200      +e1 = ef2v(u, EF, hEF)
201      +eq = top_q(one, h1, q, hq, h53)
202      +two = Nat.double(one)
203      +eE = Equal.trans(Nat, Nat.sub(Nat.add(1n+u, 1075n), SF.zb()), 2n+EF, Nat.add(two, EF), e1, Equal.cong(Nat, Nat, z => Nat.add(Nat.double(z), EF), 1n, one, Equal.sym(Nat, one, 1n, h1)))
204      +hle = Equal.trans(Bool, Nat.is_le(2047n, Nat.sub(Nat.add(1n+u, 1075n), SF.zb())), Nat.is_le(2047n, 2n+EF), False{}, Equal.cong(Nat, Bool, z => Nat.is_le(2047n, z), Nat.sub(Nat.add(1n+u, 1075n), SF.zb()), 2n+EF, e1), Equal.trans(Bool, Nat.is_le(2047n, 2n+EF), Bool.not(Nat.is_lt(2n+EF, 2047n)), False{}, FB.le_nlt(2047n, 2n+EF), Equal.cong(Bool, Bool, t => Bool.not(t), Nat.is_lt(2n+EF, 2047n), True{}, L.subst(Nat, z => {Nat.is_lt(z, 2047n) == True{} : Bool}, Nat.add(EF, 2n), 2n+EF, Equal.trans(Nat, Nat.add(EF, 2n), Nat.add(2n, EF), 2n+EF, NA.add_comm(EF, 2n), {==}), hov))))
205      +p1 = Equal.cong(Bool, F.F64, t => SF.pick(F.F64, t, SF.inf(s), SF.encode(s, Nat.sub(Nat.add(1n+u, 1075n), SF.zb()), 0n)), Nat.is_le(2047n, Nat.sub(Nat.add(1n+u, 1075n), SF.zb())), False{}, hle)
206      +p2 = enc_bits(s, Nat.sub(Nat.add(1n+u, 1075n), SF.zb()), 0n)
207      +v1 = Equal.trans(Nat, C.shift(52n, Nat.sub(Nat.add(1n+u, 1075n), SF.zb())), C.shift(52n, Nat.add(two, EF)), Nat.add(q, C.shift(52n, EF)), Equal.cong(Nat, Nat, z => C.shift(52n, z), Nat.sub(Nat.add(1n+u, 1075n), SF.zb()), Nat.add(two, EF), eE), Equal.trans(Nat, C.shift(52n, Nat.add(two, EF)), Nat.add(C.shift(52n, two), C.shift(52n, EF)), Nat.add(q, C.shift(52n, EF)), WW.shift_add(52n, two, EF), Equal.cong(Nat, Nat, z => Nat.add(z, C.shift(52n, EF)), C.shift(52n, two), q, Equal.sym(Nat, q, C.shift(52n, two), eq))))
208      +p3 = Equal.cong(Nat, F.F64, z => bits(s, z), C.shift(52n, Nat.sub(Nat.add(1n+u, 1075n), SF.zb())), Nat.add(q, C.shift(52n, EF)), v1)
209      Equal.trans(F.F64, SF.pack_e(s, Nat.sub(Nat.add(1n+u, 1075n), SF.zb()), 0n), SF.encode(s, Nat.sub(Nat.add(1n+u, 1075n), SF.zb()), 0n), bits(s, Nat.add(q, C.shift(52n, EF))), p1, Equal.trans(F.F64, SF.encode(s, Nat.sub(Nat.add(1n+u, 1075n), SF.zb()), 0n), bits(s, Nat.add(0n, C.shift(52n, Nat.sub(Nat.add(1n+u, 1075n), SF.zb())))), bits(s, Nat.add(q, C.shift(52n, EF))), p2, p3))
210
211def pkg(+one: Nat, +h1: {one == 1n : Nat}, +s: Bool, +q: Nat, +u: Nat, +EF: Nat, +hEF: {Nat.add(EF, 1926n) == u : Nat}, +hq: {Nat.is_le(q, C.shift(53n, one)) == True{} : Bool}, +h0: {Bool.or(Bool.not(C.fits(52n, q)), Nat.is_eq(EF, 0n)) == True{} : Bool}, +hov: {Nat.is_lt(Nat.add(EF, SF.pick(Nat, C.fits(53n, q), 1n, 2n)), 2047n) == True{} : Bool}) -> {SF.pack(s, q, u) == bits(s, Nat.add(q, C.shift(52n, EF))) : F.F64}:
212  pkg_c(one, h1, s, q, u, EF, hEF, hq, C.fits(53n, q), {==}, C.fits(52n, q), {==}, h0, hov)
213
214def hsp(+m: Nat) -> {C.high(10n, Nat.add(m, 512n)) == Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))) : Nat}:
215  Equal.trans(Nat, C.high(10n, Nat.add(m, 512n)), C.high(10n, Nat.add(Nat.add(C.low(10n, m), C.shift(10n, C.high(10n, m))), 512n)), Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), Equal.cong(Nat, Nat, z => C.high(10n, Nat.add(z, 512n)), m, Nat.add(C.low(10n, m), C.shift(10n, C.high(10n, m))), WW.low_high(10n, m)), Equal.trans(Nat, C.high(10n, Nat.add(Nat.add(C.low(10n, m), C.shift(10n, C.high(10n, m))), 512n)), C.high(10n, Nat.add(Nat.add(C.low(10n, m), 512n), C.shift(10n, C.high(10n, m)))), Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), Equal.cong(Nat, Nat, z => C.high(10n, z), Nat.add(Nat.add(C.low(10n, m), C.shift(10n, C.high(10n, m))), 512n), Nat.add(Nat.add(C.low(10n, m), 512n), C.shift(10n, C.high(10n, m))), A.add_rot(C.low(10n, m), C.shift(10n, C.high(10n, m)), 512n)), Equal.trans(Nat, C.high(10n, Nat.add(Nat.add(C.low(10n, m), 512n), C.shift(10n, C.high(10n, m)))), Nat.add(C.high(10n, Nat.add(C.low(10n, m), 512n)), C.high(10n, m)), Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), WW.high_add_shift(10n, Nat.add(C.low(10n, m), 512n), C.high(10n, m)), NA.add_comm(C.high(10n, Nat.add(C.low(10n, m), 512n)), C.high(10n, m)))))
216
217def mod_sh(+k: Nat, +x: Nat) -> {Nat.mod(C.shift(1n+k, x), 2n) == 0n : Nat}:
218  WW.odd_limb(k, 0n, x)
219
220def fsub_c(+k: Nat, +one: Nat, +h1: {one == 1n : Nat}, +R0: Nat, +hR: {Nat.is_le(R0, C.shift(1n+k, one)) == True{} : Bool}, +f: Bool, +hf: {C.fits(1n+k, R0) == f : Bool}) -> {C.fits(1n+k, Nat.sub(R0, Nat.mod(R0, 2n))) == f : Bool}:
221  match f:
222    case True{}:
223      SH.fits_lek(1n+k, Nat.sub(R0, Nat.mod(R0, 2n)), R0, UH.sub_le(R0, Nat.mod(R0, 2n)), hf)
224    case False{}:
225      +hlt = Equal.trans(Bool, Nat.is_lt(R0, C.shift(1n+k, one)), C.fits(1n+k, R0), False{}, lt_fit(1n+k, one, h1, R0), hf)
226      +eR = N.le_antisym(R0, C.shift(1n+k, one), hR, N.not_lt_le(R0, C.shift(1n+k, one), hlt))
227      +em = Equal.trans(Nat, Nat.mod(R0, 2n), Nat.mod(C.shift(1n+k, one), 2n), 0n, Equal.cong(Nat, Nat, z => Nat.mod(z, 2n), R0, C.shift(1n+k, one), eR), mod_sh(k, one))
228      +es = Equal.trans(Nat, Nat.sub(R0, Nat.mod(R0, 2n)), Nat.sub(R0, 0n), R0, Equal.cong(Nat, Nat, z => Nat.sub(R0, z), Nat.mod(R0, 2n), 0n, em), N.sub_zero(R0))
229      Equal.trans(Bool, C.fits(1n+k, Nat.sub(R0, Nat.mod(R0, 2n))), C.fits(1n+k, R0), False{}, Equal.cong(Nat, Bool, z => C.fits(1n+k, z), Nat.sub(R0, Nat.mod(R0, 2n)), R0, es), hf)
230
231def fpk(+one: Nat, +h1: {one == 1n : Nat}, +R0: Nat, +hR: {Nat.is_le(R0, C.shift(53n, one)) == True{} : Bool}, +t: Bool) -> {C.fits(53n, SF.pick(Nat, t, Nat.sub(R0, Nat.mod(R0, 2n)), R0)) == C.fits(53n, R0) : Bool}:
232  match t:
233    case True{}:
234      fsub_c(52n, one, h1, R0, hR, C.fits(53n, R0), {==})
235    case False{}:
236      {==}
237
238def le1(+t: Nat, +h: {C.fits(1n, t) == True{} : Bool}) -> {Nat.is_le(t, 1n) == True{} : Bool}:
239  match t:
240    case 0n:
241      {==}
242    case 1n:
243      {==}
244    case 2n+ +p:
245      NC.absurd_tf({Nat.is_le(2n+p, 1n) == True{} : Bool}, h)
246
247def R_le(+one: Nat, +h1: {one == 1n : Nat}, +m: Nat, +hm: {C.fits(63n, m) == True{} : Bool}) -> {Nat.is_le(Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), C.shift(53n, one)) == True{} : Bool}:
248  +t = C.high(10n, Nat.add(C.low(10n, m), 512n))
249  +ht = le1(t, SH.fits_high(10n, 1n, Nat.add(C.low(10n, m), 512n), fits_add1(10n, C.low(10n, m), 512n, WW.low_fits(10n, m), {==})))
250  +hq = WW.lt_one(53n, one, h1, C.high(10n, m), SH.fits_high(10n, 53n, m, hm))
251  N.le_trans(Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), Nat.add(C.high(10n, m), 1n), C.shift(53n, one), N.le_add_left(t, 1n, C.high(10n, m), ht), succ_le(C.high(10n, m), C.shift(53n, one), hq))
252
253def p2(+one: Nat, +h1: {one == 1n : Nat}, +m: Nat, +hm: {C.fits(63n, m) == True{} : Bool}) -> {C.fits(53n, SF.rne(m, 10n)) == C.fits(63n, Nat.add(m, 512n)) : Bool}:
254  +e1 = Equal.cong(Nat, Bool, z => C.fits(53n, z), SF.rne(m, 10n), SF.pick(Nat, Nat.is_eq(C.low(10n, m), 512n), Nat.sub(Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), Nat.mod(Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), 2n)), Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n)))), Equal.sym(Nat, SF.pick(Nat, Nat.is_eq(C.low(10n, m), 512n), Nat.sub(Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), Nat.mod(Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), 2n)), Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n)))), SF.rne(m, 10n), rp_c(C.high(10n, m), C.low(10n, m), WW.low_fits(10n, m), Nat.cmp(C.low(10n, m), 512n), {==})))
255  +e2 = fpk(one, h1, Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), R_le(one, h1, m, hm), Nat.is_eq(C.low(10n, m), 512n))
256  +e3 = Equal.cong(Nat, Bool, z => C.fits(53n, z), Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), C.high(10n, Nat.add(m, 512n)), Equal.sym(Nat, C.high(10n, Nat.add(m, 512n)), Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), hsp(m)))
257  +e4 = Equal.sym(Bool, C.fits(63n, Nat.add(m, 512n)), C.fits(53n, C.high(10n, Nat.add(m, 512n))), fits_hc(10n, 53n, Nat.add(m, 512n)))
258  Equal.trans(Bool, C.fits(53n, SF.rne(m, 10n)), C.fits(53n, SF.pick(Nat, Nat.is_eq(C.low(10n, m), 512n), Nat.sub(Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), Nat.mod(Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), 2n)), Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))))), C.fits(63n, Nat.add(m, 512n)), e1, Equal.trans(Bool, C.fits(53n, SF.pick(Nat, Nat.is_eq(C.low(10n, m), 512n), Nat.sub(Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), Nat.mod(Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))), 2n)), Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n))))), C.fits(53n, Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n)))), C.fits(63n, Nat.add(m, 512n)), e2, Equal.trans(Bool, C.fits(53n, Nat.add(C.high(10n, m), C.high(10n, Nat.add(C.low(10n, m), 512n)))), C.fits(53n, C.high(10n, Nat.add(m, 512n))), C.fits(63n, Nat.add(m, 512n)), e3, e4)))
259
260def sub_cancel_r(+a: Nat, +b: Nat, +c: Nat) -> {Nat.sub(Nat.add(a, c), Nat.add(b, c)) == Nat.sub(a, b) : Nat}:
261  match c:
262    case 0n:
263      Equal.trans(Nat, Nat.sub(Nat.add(a, 0n), Nat.add(b, 0n)), Nat.sub(a, Nat.add(b, 0n)), Nat.sub(a, b), Equal.cong(Nat, Nat, z => Nat.sub(z, Nat.add(b, 0n)), Nat.add(a, 0n), a, N.add_zero(a)), Equal.cong(Nat, Nat, z => Nat.sub(a, z), Nat.add(b, 0n), b, N.add_zero(b)))
264    case 1n+ +cp:
265      Equal.trans(Nat, Nat.sub(Nat.add(a, 1n+cp), Nat.add(b, 1n+cp)), Nat.sub(1n+Nat.add(a, cp), Nat.add(b, 1n+cp)), Nat.sub(a, b), Equal.cong(Nat, Nat, z => Nat.sub(z, Nat.add(b, 1n+cp)), Nat.add(a, 1n+cp), 1n+Nat.add(a, cp), N.add_succ(a, cp)), Equal.trans(Nat, Nat.sub(1n+Nat.add(a, cp), Nat.add(b, 1n+cp)), Nat.sub(1n+Nat.add(a, cp), 1n+Nat.add(b, cp)), Nat.sub(a, b), Equal.cong(Nat, Nat, z => Nat.sub(1n+Nat.add(a, cp), z), Nat.add(b, 1n+cp), 1n+Nat.add(b, cp), N.add_succ(b, cp)), sub_cancel_r(a, b, cp)))
266
267def lt0f(+h: Nat) -> {Nat.is_lt(h, 0n) == False{} : Bool}:
268  N.not_lt_zero(h)
269
270def rne_exact(+k: Nat, +m: Nat) -> {SF.rne(C.shift(k, m), k) == m : Nat}:
271  match k:
272    case 0n:
273      {==}
274    case 1n+ +i:
275      +S = C.shift(1n+i, m)
276      +h = C.shift(i, 1n)
277      +eq = WW.high_u(1n+i, 0n, m, fz(1n+i))
278      +el = WW.low_u(1n+i, 0n, m, fz(1n+i))
279      +e1 = Equal.cong(Nat, Nat, z => SF.rne_up(z, C.low(1n+i, S), h), C.high(1n+i, S), m, eq)
280      +e2 = Equal.cong(Nat, Nat, z => SF.rne_up(m, z, h), C.low(1n+i, S), 0n, el)
281      +hz = N.is_eq_sym_false(h, 0n, Equal.trans(Bool, Nat.is_eq(h, 0n), Nat.is_eq(1n, 0n), False{}, WW.shift_eq0(i, 1n), {==}))
282      +e3 = Equal.cong(Bool, Nat, t => Nat.add(m, SF.b2n(Bool.or(t, Bool.and(Nat.is_eq(0n, h), Nat.is_eq(Nat.mod(m, 2n), 1n))))), Nat.is_lt(h, 0n), False{}, lt0f(h))
283      +e4 = Equal.cong(Bool, Nat, t => Nat.add(m, SF.b2n(Bool.or(False{}, Bool.and(t, Nat.is_eq(Nat.mod(m, 2n), 1n))))), Nat.is_eq(0n, h), False{}, hz)
284      +e5 = N.add_zero(m)
285      Equal.trans(Nat, SF.rne_up(C.high(1n+i, S), C.low(1n+i, S), h), SF.rne_up(m, C.low(1n+i, S), h), m, e1, Equal.trans(Nat, SF.rne_up(m, C.low(1n+i, S), h), SF.rne_up(m, 0n, h), m, e2, Equal.trans(Nat, SF.rne_up(m, 0n, h), Nat.add(m, SF.b2n(Bool.or(False{}, Bool.and(Nat.is_eq(0n, h), Nat.is_eq(Nat.mod(m, 2n), 1n))))), m, e3, Equal.trans(Nat, Nat.add(m, SF.b2n(Bool.or(False{}, Bool.and(Nat.is_eq(0n, h), Nat.is_eq(Nat.mod(m, 2n), 1n))))), Nat.add(m, 0n), m, e4, e5))))
286
287def rne_shift(+k: Nat, +m: Nat, +j: Nat) -> {SF.rne(C.shift(k, m), Nat.add(j, k)) == SF.rne(m, j) : Nat}:
288  match j:
289    case 0n:
290      rne_exact(k, m)
291    case 1n+ +i:
292      +a = Nat.add(1n+i, k)
293      +ea = NA.add_comm(1n+i, k)
294      +hq = Equal.trans(Nat, C.high(a, C.shift(k, m)), C.high(Nat.add(k, 1n+i), C.shift(k, m)), C.high(1n+i, m), Equal.cong(Nat, Nat, z => C.high(z, C.shift(k, m)), a, Nat.add(k, 1n+i), ea), Equal.trans(Nat, C.high(Nat.add(k, 1n+i), C.shift(k, m)), C.high(1n+i, C.high(k, C.shift(k, m))), C.high(1n+i, m), WW.high_comp(1n+i, k, C.shift(k, m)), Equal.cong(Nat, Nat, z => C.high(1n+i, z), C.high(k, C.shift(k, m)), m, WW.high_u(k, 0n, m, fz(k)))))
295      +hl = Equal.trans(Nat, C.low(a, C.shift(k, m)), C.low(Nat.add(k, 1n+i), C.shift(k, m)), C.shift(k, C.low(1n+i, m)), Equal.cong(Nat, Nat, z => C.low(z, C.shift(k, m)), a, Nat.add(k, 1n+i), ea), WW.low_shift(k, 1n+i, m))
296      +hh = Equal.trans(Nat, C.shift(Nat.add(i, k), 1n), C.shift(Nat.add(k, i), 1n), C.shift(k, C.shift(i, 1n)), Equal.cong(Nat, Nat, z => C.shift(z, 1n), Nat.add(i, k), Nat.add(k, i), NA.add_comm(i, k)), WW.shift_comp(k, i, 1n))
297      +hc = Equal.trans(Cmp, Nat.cmp(C.low(a, C.shift(k, m)), C.shift(Nat.add(i, k), 1n)), Nat.cmp(C.shift(k, C.low(1n+i, m)), C.shift(Nat.add(i, k), 1n)), Nat.cmp(C.low(1n+i, m), C.shift(i, 1n)), Equal.cong(Nat, Cmp, z => Nat.cmp(z, C.shift(Nat.add(i, k), 1n)), C.low(a, C.shift(k, m)), C.shift(k, C.low(1n+i, m)), hl), Equal.trans(Cmp, Nat.cmp(C.shift(k, C.low(1n+i, m)), C.shift(Nat.add(i, k), 1n)), Nat.cmp(C.shift(k, C.low(1n+i, m)), C.shift(k, C.shift(i, 1n))), Nat.cmp(C.low(1n+i, m), C.shift(i, 1n)), Equal.cong(Nat, Cmp, z => Nat.cmp(C.shift(k, C.low(1n+i, m)), z), C.shift(Nat.add(i, k), 1n), C.shift(k, C.shift(i, 1n)), hh), NC.cmp_shift(k, C.low(1n+i, m), C.shift(i, 1n))))
298      +l1 = rne_cmp(C.high(a, C.shift(k, m)), C.low(a, C.shift(k, m)), C.shift(Nat.add(i, k), 1n))
299      +l2 = Equal.cong(Nat, Nat, z => rne_c(z, Nat.cmp(C.low(a, C.shift(k, m)), C.shift(Nat.add(i, k), 1n))), C.high(a, C.shift(k, m)), C.high(1n+i, m), hq)
300      +l3 = Equal.cong(Cmp, Nat, t => rne_c(C.high(1n+i, m), t), Nat.cmp(C.low(a, C.shift(k, m)), C.shift(Nat.add(i, k), 1n)), Nat.cmp(C.low(1n+i, m), C.shift(i, 1n)), hc)
301      +r1 = rne_cmp(C.high(1n+i, m), C.low(1n+i, m), C.shift(i, 1n))
302      Equal.trans(Nat, SF.rne_up(C.high(a, C.shift(k, m)), C.low(a, C.shift(k, m)), C.shift(Nat.add(i, k), 1n)), rne_c(C.high(1n+i, m), Nat.cmp(C.low(1n+i, m), C.shift(i, 1n))), SF.rne_up(C.high(1n+i, m), C.low(1n+i, m), C.shift(i, 1n)), Equal.trans(Nat, SF.rne_up(C.high(a, C.shift(k, m)), C.low(a, C.shift(k, m)), C.shift(Nat.add(i, k), 1n)), rne_c(C.high(a, C.shift(k, m)), Nat.cmp(C.low(a, C.shift(k, m)), C.shift(Nat.add(i, k), 1n))), rne_c(C.high(1n+i, m), Nat.cmp(C.low(1n+i, m), C.shift(i, 1n))), l1, Equal.trans(Nat, rne_c(C.high(a, C.shift(k, m)), Nat.cmp(C.low(a, C.shift(k, m)), C.shift(Nat.add(i, k), 1n))), rne_c(C.high(1n+i, m), Nat.cmp(C.low(a, C.shift(k, m)), C.shift(Nat.add(i, k), 1n))), rne_c(C.high(1n+i, m), Nat.cmp(C.low(1n+i, m), C.shift(i, 1n))), l2, l3)), Equal.sym(Nat, SF.rne_up(C.high(1n+i, m), C.low(1n+i, m), C.shift(i, 1n)), rne_c(C.high(1n+i, m), Nat.cmp(C.low(1n+i, m), C.shift(i, 1n))), r1))
303
304def bl_fit(+n: Nat) -> {C.fits(M.bit_length(n), n) == True{} : Bool}:
305  WW.fits_of_lt(M.bit_length(n), n, BT.bit_length_lt(n))
306
307def bl_nfit(+n: Nat, +hz: {Nat.is_eq(n, 0n) == False{} : Bool}) -> {C.fits(Nat.sub(M.bit_length(n), 1n), n) == False{} : Bool}:
308  +K = Nat.sub(M.bit_length(n), 1n)
309  +nf = Equal.trans(Bool, C.fits(K, C.pow2(K)), Nat.is_lt(C.pow2(K), C.pow2(K)), False{}, WW.fits_lt(K, C.pow2(K)), N.lt_irrefl(C.pow2(K)))
310  nfit(K, C.pow2(K), n, FO.lower(n, hz), nf)
311
312def fits_sh(+k: Nat, +a: Nat, +m: Nat) -> {C.fits(Nat.add(k, a), C.shift(k, m)) == C.fits(a, m) : Bool}:
313  Equal.cong(Nat, Bool, z => Nat.is_eq(z, 0n), C.high(Nat.add(k, a), C.shift(k, m)), C.high(a, m), Equal.trans(Nat, C.high(Nat.add(k, a), C.shift(k, m)), C.high(a, C.high(k, C.shift(k, m))), C.high(a, m), WW.high_comp(a, k, C.shift(k, m)), Equal.cong(Nat, Nat, z => C.high(a, z), C.high(k, C.shift(k, m)), m, WW.high_u(k, 0n, m, fz(k)))))
314
315def bl_shift(+k: Nat, +m: Nat, +hz: {Nat.is_eq(m, 0n) == False{} : Bool}) -> {M.bit_length(C.shift(k, m)) == Nat.add(M.bit_length(m), k) : Nat}:
316  +B = M.bit_length(m)
317  +j = Nat.sub(B, 1n)
318  +ej = N.sub_add(B, 1n, FO.bl_pos(m, hz, B, {==}))
319  +nf = Equal.trans(Bool, C.fits(Nat.add(k, j), C.shift(k, m)), C.fits(j, m), False{}, fits_sh(k, j, m), bl_nfit(m, hz))
320  +f0 = L.subst(Nat, z => {C.fits(z, m) == True{} : Bool}, B, 1n+j, Equal.sym(Nat, 1n+j, B, ej), bl_fit(m))
321  +f1 = Equal.trans(Bool, C.fits(Nat.add(k, 1n+j), C.shift(k, m)), C.fits(1n+j, m), True{}, fits_sh(k, 1n+j, m), f0)
322  +f2 = L.subst(Nat, z => {C.fits(z, C.shift(k, m)) == True{} : Bool}, Nat.add(k, 1n+j), 1n+Nat.add(k, j), N.add_succ(k, j), f1)
323  +eb = bl_c(Nat.add(k, j), C.shift(k, m), nf, f2, Nat.cmp(M.bit_length(C.shift(k, m)), 1n+Nat.add(k, j)), {==})
324  +er = Equal.trans(Nat, Nat.add(B, k), Nat.add(1n+j, k), 1n+Nat.add(k, j), Equal.cong(Nat, Nat, z => Nat.add(z, k), B, 1n+j, Equal.sym(Nat, 1n+j, B, ej)), Equal.cong(Nat, Nat, z => 1n+z, Nat.add(j, k), Nat.add(k, j), NA.add_comm(j, k)))
325  Equal.trans(Nat, M.bit_length(C.shift(k, m)), 1n+Nat.add(k, j), Nat.add(B, k), eb, Equal.sym(Nat, Nat.add(B, k), 1n+Nat.add(k, j), er))
326
327def a1(+x: Nat, +k: Nat, +u: Nat, +h: {Nat.is_le(Nat.add(x, k), u) == True{} : Bool}) -> {Nat.sub(u, x) == Nat.add(Nat.sub(u, Nat.add(x, k)), k) : Nat}:
328  +r = Nat.sub(u, Nat.add(x, k))
329  +eu = N.sub_add(u, Nat.add(x, k), h)
330  Equal.trans(Nat, Nat.sub(u, x), Nat.sub(Nat.add(Nat.add(x, k), r), x), Nat.add(r, k), Equal.cong(Nat, Nat, z => Nat.sub(z, x), u, Nat.add(Nat.add(x, k), r), Equal.sym(Nat, Nat.add(Nat.add(x, k), r), u, eu)), Equal.trans(Nat, Nat.sub(Nat.add(Nat.add(x, k), r), x), Nat.sub(Nat.add(x, Nat.add(k, r)), x), Nat.add(r, k), Equal.cong(Nat, Nat, z => Nat.sub(z, x), Nat.add(Nat.add(x, k), r), Nat.add(x, Nat.add(k, r)), NA.add_assoc(x, k, r)), Equal.trans(Nat, Nat.sub(Nat.add(x, Nat.add(k, r)), x), Nat.add(k, r), Nat.add(r, k), N.add_sub_cancel(x, Nat.add(k, r)), NA.add_comm(k, r))))
331
332def qeq_f(+k: Nat, +m: Nat, +x: Nat, +u: Nat, +c1: Bool, +hc1: {Nat.is_le(x, u) == c1 : Bool}, +hc2: {Nat.is_le(Nat.add(x, k), u) == False{} : Bool}) -> {SF.pick(Nat, c1, SF.rne(C.shift(k, m), Nat.sub(u, x)), C.shift(Nat.sub(x, u), C.shift(k, m))) == C.shift(Nat.sub(Nat.add(x, k), u), m) : Nat}:
333  match c1:
334    case True{}:
335      +t = Nat.sub(u, x)
336      +eu = N.sub_add(u, x, hc1)
337      +hlt0 = N.not_le_lt(Nat.add(x, k), u, hc2)
338      +hlt1 = L.subst(Nat, z => {Nat.is_lt(z, Nat.add(x, k)) == True{} : Bool}, u, Nat.add(x, t), Equal.sym(Nat, Nat.add(x, t), u, eu), hlt0)
339      +hlt2 = Equal.trans(Bool, Nat.is_lt(t, k), Nat.is_lt(Nat.add(x, t), Nat.add(x, k)), True{}, Equal.sym(Bool, Nat.is_lt(Nat.add(x, t), Nat.add(x, k)), Nat.is_lt(t, k), WW.lt_cancel_l(x, t, k)), hlt1)
340      +htk = N.lt_le(t, k, hlt2)
341      +es = NC.sh_split(k, t, m, htk)
342      +e1 = Equal.trans(Nat, SF.rne(C.shift(k, m), t), SF.rne(C.shift(t, C.shift(Nat.sub(k, t), m)), t), C.shift(Nat.sub(k, t), m), Equal.cong(Nat, Nat, z => SF.rne(z, t), C.shift(k, m), C.shift(t, C.shift(Nat.sub(k, t), m)), es), rne_exact(t, C.shift(Nat.sub(k, t), m)))
343      +e2 = Equal.trans(Nat, Nat.sub(k, t), Nat.sub(Nat.add(k, x), Nat.add(t, x)), Nat.sub(Nat.add(x, k), u), Equal.sym(Nat, Nat.sub(Nat.add(k, x), Nat.add(t, x)), Nat.sub(k, t), sub_cancel_r(k, t, x)), Equal.trans(Nat, Nat.sub(Nat.add(k, x), Nat.add(t, x)), Nat.sub(Nat.add(x, k), Nat.add(t, x)), Nat.sub(Nat.add(x, k), u), Equal.cong(Nat, Nat, z => Nat.sub(z, Nat.add(t, x)), Nat.add(k, x), Nat.add(x, k), NA.add_comm(k, x)), Equal.cong(Nat, Nat, z => Nat.sub(Nat.add(x, k), z), Nat.add(t, x), u, Equal.trans(Nat, Nat.add(t, x), Nat.add(x, t), u, NA.add_comm(t, x), eu))))
344      Equal.trans(Nat, SF.rne(C.shift(k, m), t), C.shift(Nat.sub(k, t), m), C.shift(Nat.sub(Nat.add(x, k), u), m), e1, Equal.cong(Nat, Nat, z => C.shift(z, m), Nat.sub(k, t), Nat.sub(Nat.add(x, k), u), e2))
345    case False{}:
346      +hux = N.lt_le(u, x, N.not_le_lt(x, u, hc1))
347      Equal.trans(Nat, C.shift(Nat.sub(x, u), C.shift(k, m)), C.shift(Nat.add(Nat.sub(x, u), k), m), C.shift(Nat.sub(Nat.add(x, k), u), m), Equal.sym(Nat, C.shift(Nat.add(Nat.sub(x, u), k), m), C.shift(Nat.sub(x, u), C.shift(k, m)), WW.shift_comp(Nat.sub(x, u), k, m)), Equal.cong(Nat, Nat, z => C.shift(z, m), Nat.add(Nat.sub(x, u), k), Nat.sub(Nat.add(x, k), u), Equal.sym(Nat, Nat.sub(Nat.add(x, k), u), Nat.add(Nat.sub(x, u), k), sub_add_r(x, k, u, hux))))
348
349def qeq_c(+k: Nat, +m: Nat, +x: Nat, +u: Nat, +c1: Bool, +hc1: {Nat.is_le(x, u) == c1 : Bool}, +c2: Bool, +hc2: {Nat.is_le(Nat.add(x, k), u) == c2 : Bool}) -> {SF.pick(Nat, c1, SF.rne(C.shift(k, m), Nat.sub(u, x)), C.shift(Nat.sub(x, u), C.shift(k, m))) == SF.pick(Nat, c2, SF.rne(m, Nat.sub(u, Nat.add(x, k))), C.shift(Nat.sub(Nat.add(x, k), u), m)) : Nat}:
350  match c2:
351    case True{}:
352      +h1 = N.le_trans(x, Nat.add(x, k), u, N.le_add_right(x, k), hc2)
353      +ec1 = Equal.trans(Bool, c1, Nat.is_le(x, u), True{}, Equal.sym(Bool, Nat.is_le(x, u), c1, hc1), h1)
354      +r = Nat.sub(u, Nat.add(x, k))
355      +base = Equal.trans(Nat, SF.rne(C.shift(k, m), Nat.sub(u, x)), SF.rne(C.shift(k, m), Nat.add(r, k)), SF.rne(m, r), Equal.cong(Nat, Nat, z => SF.rne(C.shift(k, m), z), Nat.sub(u, x), Nat.add(r, k), a1(x, k, u, hc2)), rne_shift(k, m, r))
356      L.subst(Bool, t => {SF.pick(Nat, t, SF.rne(C.shift(k, m), Nat.sub(u, x)), C.shift(Nat.sub(x, u), C.shift(k, m))) == SF.rne(m, r) : Nat}, True{}, c1, Equal.sym(Bool, c1, True{}, ec1), base)
357    case False{}:
358      qeq_f(k, m, x, u, c1, hc1, hc2)
359
360def rs_c(+s: Bool, +k: Nat, +m: Nat, +x: Nat, +z: Bool, +hz: {Nat.is_eq(m, 0n) == z : Bool}) -> {SF.round(s, C.shift(k, m), x) == SF.round(s, m, Nat.add(x, k)) : F.F64}:
361  match z:
362    case True{}:
363      +e0 = Equal.trans(Bool, Nat.is_eq(C.shift(k, m), 0n), Nat.is_eq(m, 0n), True{}, WW.shift_eq0(k, m), hz)
364      Equal.trans(F.F64, SF.round(s, C.shift(k, m), x), SF.zero(s), SF.round(s, m, Nat.add(x, k)), Equal.cong(Bool, F.F64, t => SF.pick(F.F64, t, SF.zero(s), SF.round_u(s, C.shift(k, m), x, Nat.max(Nat.sub(Nat.add(x, M.bit_length(C.shift(k, m))), 53n), Nat.sub(SF.zb(), 1074n)))), Nat.is_eq(C.shift(k, m), 0n), True{}, e0), Equal.sym(F.F64, SF.round(s, m, Nat.add(x, k)), SF.zero(s), Equal.cong(Bool, F.F64, t => SF.pick(F.F64, t, SF.zero(s), SF.round_u(s, m, Nat.add(x, k), Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n)))), Nat.is_eq(m, 0n), True{}, hz)))
365    case False{}:
366      +B = M.bit_length(m)
367      +e0 = Equal.trans(Bool, Nat.is_eq(C.shift(k, m), 0n), Nat.is_eq(m, 0n), False{}, WW.shift_eq0(k, m), hz)
368      +l1 = Equal.cong(Bool, F.F64, t => SF.pick(F.F64, t, SF.zero(s), SF.round_u(s, C.shift(k, m), x, Nat.max(Nat.sub(Nat.add(x, M.bit_length(C.shift(k, m))), 53n), Nat.sub(SF.zb(), 1074n)))), Nat.is_eq(C.shift(k, m), 0n), False{}, e0)
369      +ea = Equal.trans(Nat, Nat.add(x, Nat.add(B, k)), Nat.add(x, Nat.add(k, B)), Nat.add(Nat.add(x, k), B), Equal.cong(Nat, Nat, z => Nat.add(x, z), Nat.add(B, k), Nat.add(k, B), NA.add_comm(B, k)), Equal.sym(Nat, Nat.add(Nat.add(x, k), B), Nat.add(x, Nat.add(k, B)), NA.add_assoc(x, k, B)))
370      +eu = Equal.trans(Nat, Nat.max(Nat.sub(Nat.add(x, M.bit_length(C.shift(k, m))), 53n), Nat.sub(SF.zb(), 1074n)), Nat.max(Nat.sub(Nat.add(x, Nat.add(B, k)), 53n), Nat.sub(SF.zb(), 1074n)), Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n)), Equal.cong(Nat, Nat, w => Nat.max(Nat.sub(Nat.add(x, w), 53n), Nat.sub(SF.zb(), 1074n)), M.bit_length(C.shift(k, m)), Nat.add(B, k), bl_shift(k, m, hz)), Equal.cong(Nat, Nat, w => Nat.max(Nat.sub(w, 53n), Nat.sub(SF.zb(), 1074n)), Nat.add(x, Nat.add(B, k)), Nat.add(Nat.add(x, k), B), ea))
371      +l2 = Equal.cong(Nat, F.F64, w => SF.round_u(s, C.shift(k, m), x, w), Nat.max(Nat.sub(Nat.add(x, M.bit_length(C.shift(k, m))), 53n), Nat.sub(SF.zb(), 1074n)), Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n)), eu)
372      +l3 = Equal.cong(Nat, F.F64, w => SF.pack(s, w, Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), SF.pick(Nat, Nat.is_le(x, Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), SF.rne(C.shift(k, m), Nat.sub(Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n)), x)), C.shift(Nat.sub(x, Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), C.shift(k, m))), SF.pick(Nat, Nat.is_le(Nat.add(x, k), Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), SF.rne(m, Nat.sub(Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n)), Nat.add(x, k))), C.shift(Nat.sub(Nat.add(x, k), Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), m)), qeq_c(k, m, x, Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n)), Nat.is_le(x, Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), {==}, Nat.is_le(Nat.add(x, k), Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), {==}))
373      +r1 = Equal.cong(Bool, F.F64, t => SF.pick(F.F64, t, SF.zero(s), SF.round_u(s, m, Nat.add(x, k), Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n)))), Nat.is_eq(m, 0n), False{}, hz)
374      Equal.trans(F.F64, SF.round(s, C.shift(k, m), x), SF.round_u(s, m, Nat.add(x, k), Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), SF.round(s, m, Nat.add(x, k)), Equal.trans(F.F64, SF.round(s, C.shift(k, m), x), SF.round_u(s, C.shift(k, m), x, Nat.max(Nat.sub(Nat.add(x, M.bit_length(C.shift(k, m))), 53n), Nat.sub(SF.zb(), 1074n))), SF.round_u(s, m, Nat.add(x, k), Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), l1, Equal.trans(F.F64, SF.round_u(s, C.shift(k, m), x, Nat.max(Nat.sub(Nat.add(x, M.bit_length(C.shift(k, m))), 53n), Nat.sub(SF.zb(), 1074n))), SF.round_u(s, C.shift(k, m), x, Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), SF.round_u(s, m, Nat.add(x, k), Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), l2, l3)), Equal.sym(F.F64, SF.round(s, m, Nat.add(x, k)), SF.round_u(s, m, Nat.add(x, k), Nat.max(Nat.sub(Nat.add(Nat.add(x, k), M.bit_length(m)), 53n), Nat.sub(SF.zb(), 1074n))), r1))
375
376def round_shift(+s: Bool, +k: Nat, +m: Nat, +x: Nat) -> {SF.round(s, C.shift(k, m), x) == SF.round(s, m, Nat.add(x, k)) : F.F64}:
377  rs_c(s, k, m, x, Nat.is_eq(m, 0n), {==})
378