∀ {R : Type u_1} [inst : Monoid R] {S : Submonoid R} [inst_1 : OreLocalization.OreSet S] {r₁ r₂ : R} {s₁ s₂ : ↥S},
  r₁ /ₒ s₁ * (r₂ /ₒ s₂) = OreLocalization.oreNum r₁ s₂ * r₂ /ₒ (OreLocalization.oreDenom r₁ s₂ * s₁)