. apply Nat.le_of_succ_le_succ
  exact show x.size % 2 < 2 from Nat.mod_lt x.size (by decide)
case refine_1.refine_2
α : Type u
lt : α → α → Bool
inst✝ : LawfulLTBRel lt
x : Subarray α
k : Nat
hk : Subarray.size x / 2 ≤ k
⊢ Subarray.size x % 2 ≤ 1
no goals