Section Circle_2.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.
(** If a point is strictly inside a segment of a disk, it is strictly inside the circle. *)
(** If A and B are two points inside the circle, then all points on the segment AB are also in the circle, i.e. a circle is a convex figure. *)
(** Given two points U and V on a circle, the points of the line UV which are inside the circle are between U and V. *)
(** Given two points U and V on a circle, all points of line UV which are outside the segment UV are outside the circle. *)
(** Given two points U and V inside a circle, all points of line UV which are outside the circle are outside the segment UV. *)

Lemma col_inc2_outcs__out : forall A B U V P, InCircle U A B -> InCircle V A B ->
Col U V P -> OutCircleS P A B -> Out P U V.