English
The inverse of z in Circle corresponds to the complex conjugate of z.
Русский
Обратное элемента z в Circle соответствует комплексному сопряжению z.
LaTeX
$$$$ \\uparrow z^{-1} = \\overline{z}. $$$$
Lean4
/-- The map `fun t => exp (t * I)` from `ℝ` to the unit circle in `ℂ`. -/
def exp : C(ℝ, Circle)
where
toFun t := ⟨(t * I).exp, by simp [Submonoid.unitSphere, exp_mul_I, norm_cos_add_sin_mul_I]⟩
continuous_toFun :=
Continuous.subtype_mk (by fun_prop) (by simp [Submonoid.unitSphere, exp_mul_I, norm_cos_add_sin_mul_I])