def fixpoint

bend-collections-laws-math@1.0.0.0 · proofs/math/random/uint64n.bend:142

import Base
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/w64.bend as X
import bend-collections-laws-math@1.0.0.0/src/math/random/rand.bend as R

142def fixpoint(~S: Data, ~next: S -> WU.U64 & S, +f: Nat, +n: WU.U64, +t: WU.U64, +hi: WU.U64, +lo: WU.U64, +s: S, +h: {X.lt(lo, t) == False{} : Bool}) -> {R.retry(~S, ~next, f, n, t, R.D{hi, lo, s}) == R.D{hi, lo, s} : R.Draw<S>}:
143  match f:
144    case 0n:
145      {==}
146    case 1n+g:
147      %Equal.sym(Bool, X.lt(lo, t), False{}, h) : {R.retry(~S, ~next, g, n, t, R.again(~S, ~next, n, hi, lo, s, _)) == R.D{hi, lo, s} : R.Draw<S>}
148      fixpoint(~S, ~next, g, n, t, hi, lo, s, h)