Definition superprecise {A}  {JA: Join A}{PA: Perm_alg A}{SA: Sep_alg A}{AG: ageable A}{XA: Age_alg A} (P: pred A) :=
   forall w1 w2, P w1 -> P w2 -> comparable w1 w2 -> w1=w2.

Lemma superprecise_exactly {A} {JA: Join A}{PA: Perm_alg A}{SA: Sep_alg A}{AG: ageable A}{XA: Age_alg A}: forall w, superprecise (exactly w).