Below.none_some: def of bend-collections-laws-math@1.0.0.0
Import: import bend-collections-laws-math@1.0.0.0/proofs/math/random/below.bend as Below
Lines 82-84 of bend-collections-laws-math@1.0.0.0/proofs/math/random/below.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/proofs/math/random/below.bend&start_line=82&end_line=84

import Base
import bend-collections-laws-math@1.0.0.0/proofs/lib/logic.bend as L

def none_some(+y: Nat, e: {None{} == Some{y} : Maybe<&2, Nat>}) -> Empty:
  %Equal.sym(Maybe<&2, Nat>, None{}, Some{y}, e) : L.truth(is_some(_))
  Unit{}

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Empty
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.sym
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Unit
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/proofs/lib/logic.bend&name=truth
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/proofs/math/random/below.bend&name=is_some