Section PmapSub.
Variables (T : Type) (p : pred T) (sT : subType p).

(* Specifications: *)
Lemma size_pmap_sub s : size (pmap (insub : T -> option sT) s) = count p s.
Lemma iota_addl m1 m2 n : iota (m1 + m2) n = map (addn m1) (iota m2 n).
Lemma mem_iota m n i : (i \in iota m n) = (m <= i) && (i < m + n).
Lemma iota_uniq m n : uniq (iota m n).
End MakeSeq.