English
The forward direction of the real-linear equivalence between self-adjoint ℂ and ℝ realizes the underlying complex element unchanged when viewed back.
Русский
Прямая часть веерного перехода между самосопряжёнными элементами ℂ и ℝ сохраняет исходный комплексный элемент при возвращении из ℝ в ℂ.
LaTeX
$$$(\text{selfAdjointEquiv}\ z : \mathbb{C}) = z$ for all $z \in \mathrm{SelfAdjoint}(\mathbb{C})$, i.e., the forward map is compatible with the inclusion of real numbers into complex numbers.$$
Lean4
theorem coe_selfAdjointEquiv (z : selfAdjoint ℂ) : (selfAdjointEquiv z : ℂ) = z := by
simpa [selfAdjointEquiv_symm_apply] using (congr_arg Subtype.val <| Complex.selfAdjointEquiv.left_inv z)