law maybe_is_some_map

bend-mathlib@0.8.1.0 · maybe.bend:115

import Base

115# Mapping keeps whether a value is present.
116law maybe_is_some_map:
117  for ~A: Data
118  for ~B: Data
119  for ~f: A -> B
120  for m: Maybe<&2, A>
121  {Maybe.is_some(&2, B, Maybe.map(&2, A, B, f, m)) == Maybe.is_some(&2, A, m) : Bool}