You can search for identifiers within the package.
in-package search v0.2.0
type 'a t
val return : 'a -> 'a t
val failwith : string -> 'a t
val let+ : 'a t -> ('a -> 'b) -> 'b t
val let* : 'a t -> ('a -> 'b t) -> 'b t
val and+ : 'a t -> 'b t -> ('a * 'b) t
type in_channel
type out_channel