Variable elt':Type.
(** * [map] and [mapi] *)
Fixpoint map (f:elt -> elt') (m:t elt) : t elt' :=
match m with
| nil => nil
| (k,e)::m' => (k,f e) :: map f m'
end.
Fixpoint mapi (f: key -> elt -> elt') (m:t elt) : t elt' :=
match m with
| nil => nil
| (k,e)::m' => (k,f k e) :: mapi f m'
end.
End Elt.
Section Elt2.
(* A new section is necessary for previous definitions to work with different [elt], especially [MapsTo]... *)
Variable elt elt' : Type.
(** Specification of [map] *)

Lemma map_lelistA : forall (m: t elt)(x:key)(e:elt)(e':elt')(f:elt->elt'),
lelistA (@ltk elt) (x,e) m ->
lelistA (@ltk elt') (x,e') (map f m).