End Fin2Restrict.
(** We can now use Proof via the equivalence ... *)

(* Specifications: *)
Lemma bInjective_bSurjective n (f:nat->nat) :
bFun n f -> (bInjective n f <-> bSurjective n f).
Lemma bSurjective_bBijective n (f:nat->nat) :
bFun n f -> bSurjective n f ->
exists g, bFun n g /\ forall x, x < n -> g (f x) = x /\ f (g x) = x.