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 l10_7 : forall A B P P' Q Q', Reflect P' P A B -> Reflect Q' Q A B -> P'=Q' -> P = Q.