English
The star-algebra automorphisms of R form a group under composition.
Русский
Группа⋆ автоморфизмов ⋆-алгебры R под действием композиции.
LaTeX
$$$$ \text{Aut}_{\star}^{S}(R) \text{ is a group under composition.} $$$$
Lean4
/-- Promote a bijective star algebra homomorphism to a star algebra equivalence. -/
noncomputable def ofBijective (f : F) (hf : Function.Bijective f) : A ≃⋆ₐ[R] B :=
{
RingEquiv.ofBijective f (hf : Function.Bijective
(f : A → B)) with
toFun := f
map_star' := map_star f
map_smul' := map_smul f }