Global Instance IncidLP_morphisml : Proper(EqL ==> eq ==> iff) IncidLP.Global Instance IncidLP_morphismr : Proper(eq ==> EqP ==> iff) IncidLP.

Lemma congH_colH_betH: forall A B I, A<>B -> A<>I -> B<>I -> CongH I A I B -> ColH I A B -> BetH A I B.