have hzmem : z ∈ A := by
  simp only [Set.mem_setOf_eq]
  exact hz
motive : ↑N0 → Prop
hz : motive z
hs : ∀ (n : ↑N0), motive n → motive (S n)
x : ↑N0
A : Set ↑N0 := {x | motive x}
⊢ motive x
motive : ↑N0 → Prop
hz : motive z
hs : ∀ (n : ↑N0), motive n → motive (S n)
x : ↑N0
A : Set ↑N0 := {x | motive x}
hzmem : z ∈ A
⊢ motive x