Section T11_1.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma l11_aux : forall B A A' A0 E D D' D0,
Out B A A' -> Out E D D' -> Cong B A' E D' ->
Bet B A A0 -> Bet E D D0 -> Cong A A0 E D ->
Cong D D0 B A ->
Cong B A0 E D0 /\ Cong A' A0 D' D0.