Adding Metatheoretic Facilities to Rst-order Theories

Generic proof systems like Isabelle provide some limited but useful metatheoretic facilities for declared logics; in particular, users can prove simple derived rules and alsòsolve' formulae that contain meta-variables | a technique useful for, e.g., program synthesis. We show how an arbitrary rst order theory can be conservatively extended to provide similar facilities, without a supporting metatheory, and examine what the limitations of this approach are.