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 (ext_link: Strings.String.string -> ident) id ids sig sig' cc A P Q NEP NEQ (fs : funspecs) : let f := mk_funspec sig cc A P Q NEP NEQ in In (ext_link id,f) fs -> funspecs_norepeat fs -> ids = fst (split (fst sig)) -> sig' = funsig2signature sig cc -> (forall n, semax_external (add_funspecs Espec ext_link fs) ids (EF_external id sig') _ P Q n).