match this with
| Or.inl (_ : p < q) =>
  have : p < r := lt_trans ‹p < q› ‹q < r›
  exact this
| Or.inr (_ : p ≃ q) =>
  have : p < r := lt_substL_eqv (eqv_symm ‹p ≃ q›) ‹q < r›
  exact this
ℕ ℤ ℚ : Type
inst✝¹⁰ : Natural ℕ
inst✝⁹ : Integer ℤ
inst✝⁸ : Core ℚ
inst✝⁷ : Addition ℚ
inst✝⁶ : Multiplication ℚ
inst✝⁵ : Negation ℚ
inst✝⁴ : Sign ℚ
inst✝³ : Subtraction ℚ
inst✝² : Reciprocation ℚ
inst✝¹ : Division ℚ
inst✝ : Order ℚ
p q r : ℚ
x✝¹ : p ≤ q
x✝ : q < r
this : p < q ∨ p ≃ q
⊢ p < r
no goals