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

Lemma th14: forall A B C D A' B' C' D', ~ ColH A B C -> ~ ColH A' B' C' -> CongaH A B C A' B' C' -> BetH A B D -> BetH A' B' D' -> CongaH C B D C' B' D'.