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

Lemma lea_trans : forall A B C A1 B1 C1 A2 B2 C2,
LeA A B C A1 B1 C1 ->
LeA A1 B1 C1 A2 B2 C2 ->
LeA A B C A2 B2 C2.