English
If y ≥ 0, Real.toNNReal(x/y) = Real.toNNReal x / Real.toNNReal y.
Русский
Если y ≥ 0, Real.toNNReal(x/y) = Real.toNNReal x / Real.toNNReal y.
LaTeX
$$$\forall x,y \in \mathbb{R},\ y \ge 0\Rightarrow Real.toNNReal(x/y) = Real.toNNReal x / Real.toNNReal y$$$
Lean4
theorem _root_.Real.toNNReal_div' {x y : ℝ} (hy : 0 ≤ y) : Real.toNNReal (x / y) = Real.toNNReal x / Real.toNNReal y :=
by rw [div_eq_inv_mul, div_eq_inv_mul, Real.toNNReal_mul (inv_nonneg.2 hy), Real.toNNReal_inv]