Definition foldfmap g (e: C) (s: finMap A V) :=
  foldr g e (seq_of s).

(* Specifications: *)
Lemma foldf_nil g e : foldfmap g e (@nil A V) = e.
Lemma foldf_ins g e k v f: path ord k (supp f) -> foldfmap g e (ins k v f) = g (k, v) (foldfmap g e f).