> (and there may be one other requirement that I've forgotten) `map: forall a b . (a -> b) => (m a -> m b)` and `pure: forall a . a -> m a`, plus some (mostly

> (and there may be one other requirement that I've forgotten) `map: forall a b . (a -> b) => (m a -> m b)` and `pure: forall a . a -> m a`, plus some (mostly very natural) compatibility conditions between the three: `flatMap(pure)` does nothing, `map` takes the identity to the identity, etc.