refine Array.ext _ _ (by simp only [size_swap]) ?_
α : Type u
x : Array α
i j : Fin (size x)
⊢ swap x i j = swap x j i
α : Type u
x : Array α
i j : Fin (size x)
⊢ ∀ (i_1 : Nat) (hi₁ : i_1 < size (swap x i j)) (hi₂ : i_1 < size (swap x j i)), (swap x i j)[i_1] = (swap x j i)[i_1]