Instance CompSpecs : compspecs. make_compspecs prog. Defined.
Definition Gprog : funspecs :=
ltac:(with_library prog [odd_spec; even_spec]).

Lemma body_odd : semax_body Vprog Gprog f_odd odd_spec.
Definition Espec := add_funspecs NullExtension.Espec (ext_link_prog odd.prog) Gprog.