∀ {f : ZFSet.{u_1} → ZFSet.{u_1}} (x : PSet.{u_1}) (α : Type u_1) (A : α → PSet.{u_1})
  (motive : (∃ z ∈ ⟦PSet.mk α A⟧, f z = ⟦x⟧) → Prop) (x_1 : ∃ z ∈ ⟦PSet.mk α A⟧, f z = ⟦x⟧),
  (∀ (w : ZFSet.{u_1}) (hz : w ∈ ⟦PSet.mk α A⟧) (e : f w = ⟦x⟧), motive ⋯) → motive x_1