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

Lemma f_pred_positive : forall tsh sh gsh entries gh g lgk lgv p t locksp lockt resultsp res,
positive_mpred (f_lock_pred tsh sh gsh entries gh g lgk lgv p t locksp lockt resultsp res).