∀ {C : Type u_1} [inst : CategoryTheory.Category.{v_1, u_1} C] {K : CategoryTheory.Precoverage C}
  {J : CategoryTheory.GrothendieckTopology C} [K.HasPullbacks] [K.IsStableUnderBaseChange],
  K.toGrothendieck ≤ J ↔ K ≤ J.toPrecoverage