You can search for identifiers within the package.
in-package search v0.2.0
module L = BatList
val stddev : float list -> float
val enforce : bool -> (unit -> string) -> unit
val prepend2 : 'a -> ('b * 'c) -> 'a * 'b * 'c
val prepend3 : 'a -> ('b * 'c * 'd) -> 'a * 'b * 'c * 'd
val fst4 : ('a * 'b * 'c * 'd) -> 'a
val trd4 : ('a * 'b * 'c * 'd) -> 'c
val frt4 : ('a * 'b * 'c * 'd) -> 'd
val combine3 : 'a list -> 'b list -> 'c list -> ('a * 'b * 'c) list