End T7_1.
Hint Resolve l7_13 : cong.
Hint Resolve l7_2 l7_3_2 : midpoint.
Ltac Midpoint := auto with midpoint.
Section T7_2.
Context {Tn:Tarski_neutral_dimensionless}.
Context {TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality Tn}.

Lemma Mid_perm :
forall A B C,
Midpoint A B C ->
Midpoint A B C /\ Midpoint A C B.