val incr_nth : int list -> int -> int list

incr_nth l n adds one to the nth element of l.

val fill_map2 : ( int -> int -> int ) -> int list -> int list -> int list

fill_map2 f l l' padds with zeros the smaller list before applying f.

val fill_fold_left2 : ( int -> int -> int -> int ) -> int -> int list -> int list -> int

fill_fold_left2 f l l' padds with zeros the smaller list before applying f.