Definition add_funspecs (Espec : OracleKind) (ext_link: Strings.String.string -> ident) (fs : funspecs) : OracleKind :=
  match Espec with
    | Build_OracleKind ty spec =>
      Build_OracleKind ty (add_funspecs_rec ext_link ty spec fs)
  end.

Lemma semax_ext'_void (ext_link: Strings.String.string -> ident) id sig cc A P Q NEP NEQ (fs : funspecs) : let f := mk_funspec (sig, tvoid) cc A P Q NEP NEQ in In (ext_link id,f) fs -> funspecs_norepeat fs -> (forall n, semax_external (add_funspecs Espec ext_link fs) (fst (split sig)) (EF_external id (mksignature (map typ_of_type (map snd sig)) None cc)) _ P Q n).