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

Lemma congH_permlr : forall A B C D, A<>B -> C<>D -> CongH A B C D -> CongH B A D C.