(** * Addendum to the standard library of Coq *)
Require Export Omega.
Global Obligation Tactic := idtac.
Notation "[ x ; .. ; y ]" := (cons x .. (cons y nil) .. ).

Lemma map_nth_seq : forall A (l:list A) len n d,
length l = len + n ->
map (fun x : nat => nth x l d) (seq n len) = (skipn n l).