(* Box is a normal modal operator *)

(* Specifications: *)
Lemma ruleNec {A} `{ageable A} : forall M (P:pred A),
derives TT P ->
derives TT (box M P).
Lemma axiomK {A} `{ageable A}: forall M (P Q:pred A),
(box M (P --> Q)) |-- (box M P --> box M Q).