Section HilbertContext_2.
Context `{Hi:Hilbert_neutral_dimensionless}.
Definition Cong A B C D := (CongH A B C D /\ A <> B /\ C <> D) \/ (A = B /\ C = D).
(****************** between_identity ************************)
(************************************************************)
(***************************** cong_identity ***********************)
(************************ cong_inner_transitivity ****************************)

Lemma cong_inner_transitivity : forall A B C D E F, Cong A B C D -> Cong A B E F -> Cong C D E F.