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 image_in_gen_is_image : forall M A B P P', Reflect_at M P P' A B -> Reflect P P' A B.