next hnone =>
  absurd (Fin.find?_none i hnone)
  rw [decide_eq_false_iff_not]
  intro h
  apply h
  exact Setoid.refl ..
case h.mp.right.h_2
n : Nat
s : Setoid (Fin n)
inst✝ : DecidableRel Setoid.r
k : Fin (quot s)
i : Fin n
h✝ : Quotient.mk s (decodeSubtype (repr s) k).val = Quotient.mk s i
h : (decodeSubtype (repr s) k).val ≈ i
heq✝ : (Fin.find? fun b => decide (Setoid.r i b)) = none
⊢ absurd ⋯ ⋯ = k
no goals