∀ (fullName : Lean.Name) (__do_lift : Lean.NameSet),
  ¬(Std.TreeSet.toArray (Lean.NameSet.filter (fun x => decide (x.getPrefix = fullName.getPrefix)) __do_lift)).size = 0 →
    ¬0 <
          (Std.TreeSet.toArray
              (Lean.NameSet.filter (fun x => decide (x.getPrefix = fullName.getPrefix)) __do_lift)).size →
      False