English
Under subsingleton α, Subalgebra(R, C(α,R)) is a singleton; all elements equal to algebraMap R C(α,R) (fdefault) etc.
Русский
При subsingleton α подпалгебра Subalgebra(R, C(α,R)) является одиночной; все элементы совпадают с algebraMap R C(α,R) (f по умолчанию).
LaTeX
$$$\\text{SubsingletonSubalgebra} : \\text{Subsingleton}(\\text{Subalgebra}(R, C(\\alpha,R))).$$$
Lean4
/-- Evaluation of continuous maps at a point, bundled as an algebra homomorphism. -/
@[simps]
def evalAlgHom (x : X) : C(X, R) →ₐ[S] R where
toFun f := f x
map_zero' := rfl
map_one' := rfl
map_add' _ _ := rfl
map_mul' _ _ := rfl
commutes' _ := rfl