exact ih ..
case right
α : Type u_1
s : Setoid α
inst✝ : DecidableRel Setoid.r
xs✝ : List α
x : α
xs : List α
ih : ∀ (i : xs.Index), Setoid.r i.val (dedup s i).val
i : (x :: xs).Index
h : Logic.Any (List.map (Setoid.r x) xs)
⊢ Setoid.r (unmap (Setoid.r x) h.get).val (dedup s (unmap (Setoid.r x) h.get)).val
no goals