Require Export GeoCoq.Tarski_dev.Annexes.saccheri.
Section Defect.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma conga_defect__defect : forall A B C D E F D' E' F',
Defect A B C D E F -> CongA D E F D' E' F' ->
Defect A B C D' E' F'.