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_2_uniqueness : forall A B P P1 P2, Reflect P1 P A B -> Reflect P2 P A B -> P1=P2.