Corollary int_op_value_of_hist : forall h, Forall int_op (map snd h) -> tc_val tint (value_of_hist h).

Lemma index_of_app : forall k m1 m2, index_of (m1 ++ m2) k = match index_of m1 k with Some i => Some i | None => option_map (Z.add (Zlength m1)) (index_of m2 k) end.