sig
val split : 'a list -> int -> 'a list * 'a * 'a list
val replace : 'a -> 'a list -> int -> 'a list
val replace_map : ('a -> 'a) -> 'a list -> int -> 'a list
val position : 'a -> 'a list -> int
val fprintf_list : 'a Useful.fprintf -> 'a list Useful.fprintf
end