Hint Resolve l8_2 : perp.
Ltac Perp := auto with perp.
Section T8_2.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

(* Specifications: *)
Lemma Per_cases :
forall A B C,
Per A B C \/ Per C B A ->
Per A B C.
Lemma Per_perm :
forall A B C,
Per A B C ->
Per A B C /\ Per C B A.
Lemma l8_3 : forall A B C A',
Per A B C -> A<>B -> Col B A A' -> Per A' B C.
Lemma l8_4 : forall A B C C', Per A B C -> Midpoint B C C' -> Per A B C'.
Lemma l8_5 : forall A B, Per A B B.
Lemma l8_6 : forall A B C A', Per A B C -> Per A' B C -> Bet A C A' -> B=C.
End T8_2.