Section Bisector.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.
(** Existence of the interior bisector of an angle. *)

Lemma bisector_foot_out_out : forall A B C I H1 H2, ~ Col A B C ->
Coplanar A B C I -> Col B C H2-> CongA A B I I B C->
Perp A B I H1 -> Perp B C I H2 -> Out B H1 A -> Out B H2 C.