match le.dest' hle with
| ⟨0, (h : j = i + 0)⟩ =>
  right
  rw [h, Int.add_zero]
| ⟨n+1, (h : j = i + (ofNat n + 1))⟩ =>
  left
  rw [Int.lt_iff_succ_le]
  rw [h, ←Int.add_assoc, Int.add_right_comm]
  apply Int.le.intro'
i j : Int
hle : i ≤ j
⊢ i < j ∨ i = j
no goals