def half_small

bend-collections-laws-math@1.0.0.0 · proofs/math/typed/f64round.bend:104

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/proofs/math/typed/natcmp.bend as NC

104def half_small(+t: Nat, +ht: {Nat.is_le(t, 1n) == True{} : Bool}) -> {C.half(t) == 0n : Nat}:
105  match t:
106    case 0n:
107      {==}
108    case 1n:
109      {==}
110    case 2n+ +q:
111      NC.absurd_tf({C.half(2n+q) == 0n : Nat}, ht)