Definition funspec2post (ext_link: Strings.String.string -> ident) (A : TypeTree)
(Q: forall ts, dependent_type_functor_rec ts (AssertTT A) mpred)
id sig ef x ge_s (tret : option typ) ret (z : Z) m : Prop :=
match oi_eq_dec (Some (id, sig)) (ef_id_sig ext_link ef) as s
return ((if s then (rmap*(sigT (fun ts => dependent_type_functor_rec ts A mpred)))%type else ext_spec_type Espec ef) -> Prop)
with
| left _ => fun x' => exists phi0 phi1, join phi0 phi1 (m_phi m)
/\ Q (projT1 (snd x')) (projT2 (snd x')) (make_ext_rval (filter_genv (symb2genv ge_s)) ret) phi0
/\ necR (fst x') phi1 /\ joins (ghost_of (m_phi m)) (Some (ghost_PCM.ext_ref z, NoneP) :: nil)
| right n => fun x' => ext_spec_post Espec ef x' ge_s tret ret z m
end x.
Definition funspec2extspec (ext_link: Strings.String.string -> ident) (f : (ident*funspec))
: external_specification juicy_mem external_function Z :=
match f with
| (id, mk_funspec ((params, sigret) as fsig) cc A P Q NEP NEQ) =>
let sig := funsig2signature fsig cc in
Build_external_specification juicy_mem external_function Z
(fun ef => if oi_eq_dec (Some (id, sig)) (ef_id_sig ext_link ef) then (rmap* (sigT (fun ts => dependent_type_functor_rec ts A mpred)))%type else ext_spec_type Espec ef)
(funspec2pre ext_link A P (fst (split params)) id sig)
(funspec2post ext_link A Q id sig)
(fun rv z m => False)
end.
Local Open Scope pred.
Definition wf_funspec (f : funspec) :=
match f with
| mk_funspec sig cc A P Q _ _ =>
forall ts a (ge ge': genv) n args,
Genv.genv_symb ge = Genv.genv_symb ge' ->
P ts a (make_ext_args (filter_genv ge) n args) |-- P ts a (make_ext_args (filter_genv ge') n args)
end.

Lemma make_ext_args_symb (ge ge' : genv)
(H: Genv.genv_symb ge = Genv.genv_symb ge') n args :
make_ext_args (filter_genv ge) n args = make_ext_args (filter_genv ge') n args.