def d64_sbnd

bend-collections-laws-math@1.0.0.0 · proofs/math/typed/fixbytes.bend:300

import Base
import bend-collections-laws-math@1.0.0.0/spec/lib/common.bend as C
import bend-collections-laws-math@1.0.0.0/spec/math/generic.bend as SG
import bend-collections-laws-math@1.0.0.0/spec/math/fixed.bend as SF
import bend-collections-laws-math@1.0.0.0/src/math/w64.bend as X
import bend-collections-laws-math@1.0.0.0/src/math/u64.bend as WU
import bend-collections-laws-math@1.0.0.0/src/math/fixed.bend as F

300def d64_sbnd(+k: Nat, +hk: {Nat.is_le(Nat.add(8n, k), 64n) == True{} : Bool}, +z: WU.U64, +hz: {C.fits(k, SG.u64_val(z)) == True{} : Bool}, +b: U32, +c: Bool, +hc: {F.is_byte(b) == c : Bool}) -> {bnd(Nat.add(8n, k), SF.mval(~WU.U64, ~SG.u64_val, F.dig64(Some{z}, c, b))) == True{} : Bool}:
301  match c:
302    case True{}:
303      +hb = Equal.trans(Bool, C.fits(8n, v(b)), F.is_byte(b), True{}, fb(b), hc)
304      %Equal.sym(Nat, SG.u64_val(X.add(WU.U64{b, 0}, X.mul(z, WU.U64{256, 0}))), Nat.add(v(b), C.shift(8n, SG.u64_val(z))), step64(k, hk, z, hz, b, hb)) : {C.fits(Nat.add(8n, k), _) == True{} : Bool}
305      step_fits(k, v(b), SG.u64_val(z), hb, hz)
306    case False{}:
307      {==}