∀ {α : Type u} [inst : Lean.Grind.Semiring α] (q₁ q₂ : Lean.Grind.Ring.OfSemiring.Q α),
  Lean.Grind.Ring.OfSemiring.mul q₁ q₂ =
    q₁.liftOn₂ q₂
      (fun x x_1 =>
        match x with
        | (a, b) =>
          match x_1 with
          | (c, d) => Lean.Grind.Ring.OfSemiring.Q.mk (a * c + b * d, a * d + b * c))
      ⋯