Coq: local ltac definition

If there is a way to define a "local" Ltac expresion which I can use to proof a lemma but not visible outside?

Lemma Foo ...
Proof.
   Ltac ll := ...
   destrict t.
   - reflexivity.
   - ll.
   - ll.
Qed.

(* ll should not be visible here *)

You can use a section:

Section Foo.
  Ltac solve := exact I.
  Lemma Foo : True.
  Proof.
    solve.
  Qed.
End Foo.