You can search for identifiers within the package.
in-package search v0.2.0
module Public : sig ... end
include module type of struct include Public end
type ('a, 'b) either = ('a, 'b) Public.either =
| Left of 'a
| Right of 'b
val either : ('a -> 'b) -> ('c -> 'd) -> ('e, 'f) either -> 'g
type ('a, 'b) t = ('a, 'b) either
val return : 'a -> ('b, 'c) either
val (>>=) : ('a, 'b) either -> ('c -> ('d, 'e) either) -> ('d, 'e) either