Require Export GeoCoq.Tarski_dev.Ch04_col.
Section Equivalence_between_decidability_properties_of_basic_relations.
Context `{Tn:Tarski_neutral_dimensionless}.

Lemma cong_dec_eq_dec :
(forall A B C D, Cong A B C D \/ ~ Cong A B C D) ->
(forall A B:Tpoint, A=B \/ A<>B).