(* Why isn't this automatic? *)
Instance zero_ord_preorder : RelationClasses.PreOrder zero_ord.Instance table_incl_preorder : RelationClasses.PreOrder table_incl.

Lemma apply_hist_app : forall h1 h2 H H', apply_hist H (h1 ++ h2) H' <-> exists H1, apply_hist H h1 H1 /\ apply_hist H1 h2 H'.