Definition all_assertions_computable  :=
forall (Espec: OracleKind) psi tx vx (Q: assert),
exists k,  assert_safe Espec psi tx vx k = Q.
(* This is not generally true, but could be made true by adding an "assert" operator to the programming language *)

Lemma later_strengthen_safe1:
forall {Espec: OracleKind} (P: pred rmap) ge ve te k rho,
((|> P) >=> assert_safe Espec ge ve te k rho) |--   |>  (P >=> assert_safe Espec ge ve te k rho).