Admitted.

(** *Need an extra fact about simulations*)
Lemma step2corestep_plus:
forall (s1 s2: Smallstep.state (Asm.part_semantics Asm_g)) m1 t,
Smallstep.plus
(Asm.step (Genv.globalenv Asm_program))
(Smallstep.set_mem s1 m1) t s2 ->
(corestep_plus (Asm_core.Asm_core_sem Asm_g))
s1 m1 s2 (Smallstep.get_mem s2).