Applicative.Basic2
type ('a, 'e) t
val return : 'a -> ('a, _) t
val apply : ('a -> 'b, 'e) t -> ('a, 'e) t -> ('b, 'e) t
val map : [ `Define_using_apply | `Custom of ('a, 'e) t -> f:('a -> 'b) -> ('b, 'e) t ]