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_spec_dec : forall A B C D, ReflectL A B C D \/ ~ ReflectL A B C D.