Section T1_4.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma Cong_perm :
forall A B C D,
Cong A B C D ->
Cong A B C D /\ Cong A B D C /\ Cong B A C D /\ Cong B A D C /\
Cong C D A B /\ Cong C D B A /\ Cong D C A B /\ Cong D C B A.