law maybe_map_pure

bend-mathlib@0.8.1.0 · maybe.bend:45

import Base

45# Mapping a pure value is pure of the mapped value.
46law maybe_map_pure:
47  for ~A: Data
48  for ~B: Data
49  for -f: A -> B
50  for -x: A
51  {Maybe.map(&2, A, B, f, Maybe.pure(&2, A, x)) == Maybe.pure(&2, B, f(x)) : Maybe<&2, B>}