def fv

bend-collections-laws-math@1.0.0.0 · proofs/math/typed/u32int.bend:906

import Base

906# y when ok, else x: {fv(ok, v(a), x) == x} says v(a) == x when ok
907def fv(ok: Bool, +y: Nat, +x: Nat) -> Nat:
908  match ok:
909    case True{}:
910      y
911    case False{}:
912      x