Require Export GeoCoq.Meta_theory.Parallel_postulates.parallel_postulates.
Require Export GeoCoq.Meta_theory.Parallel_postulates.par_trans_NID.
Section T13.
Context `{TE:Tarski_euclidean}.

Lemma not_par_one_not_par : forall A B A' B' X Y, ~Par A B A' B' -> ~Par A B X Y \/ ~Par A' B' X Y.