English
For any real r,s and RCLike K, the real division embedded into K equals the direct division in K: ((r/s : ℝ) : K) = r/s and the reverse equality holds for division in the embedding sense.
Русский
Для любых действительных r,s и K, встроенное в K деление r/s равно самому делению в K: ((r/s : ℝ) : K) = r/s.
LaTeX
$$$$ ((r / s : \mathbb{R}) : K) = r / s. $$$$
Lean4
@[rclike_simps, norm_cast]
theorem ofReal_div (r s : ℝ) : ((r / s : ℝ) : K) = r / s :=
map_div₀ (algebraMap ℝ K) r s