End T11_1.
Section T11_2.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma l11_30 : forall A B C D E F A' B' C' D' E' F',
LeA A B C D E F ->
CongA A B C A' B' C' ->
CongA D E F D' E' F' ->
LeA A' B' C' D' E' F'.