Ltac CopR :=
 let tpoint := constr:(Tpoint) in
 let col := constr:(Col) in
 let cop := constr:(Coplanar) in
   assert_ncols; Cop_refl tpoint col cop.

Lemma is_image_col_cong : forall A B P P' X, A<>B -> Reflect P P' A B -> Col A B X -> Cong P X P' X.