(** A variant of [transl_expr_charact], for use when the destination register is the one associated with a variable. *)

Lemma transl_exitexpr_charact:
forall nexits a map s ns s' INCR
(TR: transl_exitexpr map a nexits s = OK ns s' INCR)
(WF: map_valid map s),
tr_exitexpr s'.(st_code) map a ns nexits.