Hypothesis symbols_preserved:
forall id, Senv.find_symbol ge2 id = Senv.find_symbol ge1 id.

(* Specifications: *)
Lemma eventval_match_preserved:
forall ev ty v,
eventval_match ge1 ev ty v -> eventval_match ge2 ev ty v.
Lemma eventval_list_match_preserved:
forall evl tyl vl,
eventval_list_match ge1 evl tyl vl -> eventval_list_match ge2 evl tyl vl.