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

Lemma l11_36 : forall A B C D E F A' D',
A <> B -> A' <> B -> D <> E -> D' <> E ->
Bet A B A' -> Bet D E D' ->
(LeA A B C D E F <-> LeA D' E F A' B C).