(*(Sstore chunk addr al b) effsstep tge (State f (store chunk a1 a2) k sp e m) E0 (State f Sskip k sp e m').*)
(** Correctness of instruction selection for operators *)

Lemma eval_sel_unop:
forall le op a1 v1 v,
eval_expr tge sp e m le a1 v1 ->
eval_unop op v1 = Some v ->
exists v', eval_expr tge sp e m le (sel_unop hf op a1) v' /\ Val.lessdef v v'.