Require Export GeoCoq.Tarski_dev.Ch09_plane.
Require Export GeoCoq.Tarski_dev.Tactics.CoincR_for_cop.
Ltac CopR :=
let tpoint := constr:(Tpoint) in
let col := constr:(Col) in
let cop := constr:(Coplanar) in
assert_ncols; Cop_refl tpoint col cop.
Section T10.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma midpoint_preserves_image : forall A B P P' Q Q' M,
A <> B -> Col A B M -> Reflect P P' A B ->
Midpoint M P Q -> Midpoint M P' Q' -> Reflect Q Q' A B.