Section T10_1.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma cong_cop_per2 : forall A B X Y,
A <> B -> Per A B X -> Per A B Y -> Cong B X B Y -> Coplanar A B X Y ->
X = Y \/ ReflectL X Y A B.