You can search for identifiers within the package.
in-package search v0.2.0
Variable environment.
Env.usual contains pi and e .
Env.usual
pi
e
type t
val add : string -> float -> t -> t
val mem : string -> t -> bool
val union : t -> t -> t
val of_list : (string * float) list -> t
val empty : t
val usual : t