Hint Resolve corable_funassert.
Definition allp_fun_id (Delta : tycontext) (rho : environ): pred rmap :=
(ALL id : ident ,
(ALL fs : funspec ,
!! ((glob_specs Delta) ! id = Some fs) -->
(EX b : block, !! (Map.get (ge_of rho) id = Some b) && func_at fs (b, 0)))).

Lemma funassert_allp_fun_id_sub: forall Delta Delta' rho,
tycontext_sub Delta Delta' ->
funassert Delta' rho |-- allp_fun_id Delta rho.