𝕜 : Type u_1
A : Type u_2
inst✝¹⁰ : CommRing 𝕜
inst✝⁹ : NoZeroDivisors 𝕜
inst✝⁸ : TopologicalSpace 𝕜
inst✝⁷ : ContinuousAdd 𝕜
inst✝⁶ : ContinuousConstSMul 𝕜 𝕜
inst✝⁵ : TopologicalSpace A
inst✝⁴ : Semiring A
inst✝³ : Algebra 𝕜 A
inst✝² : Nontrivial 𝕜
inst✝¹ : T2Space 𝕜
inst✝ : ContinuousMul 𝕜
⊢ IsClosed ({a | ↑a 1 = 1} ∩ {a | ∀ (x y : A), ↑a (x * y) = ↑a x * ↑a y})
𝕜 : Type u_1
A : Type u_2
inst✝¹⁰ : CommRing 𝕜
inst✝⁹ : NoZeroDivisors 𝕜
inst✝⁸ : TopologicalSpace 𝕜
inst✝⁷ : ContinuousAdd 𝕜
inst✝⁶ : ContinuousConstSMul 𝕜 𝕜
inst✝⁵ : TopologicalSpace A
inst✝⁴ : Semiring A
inst✝³ : Algebra 𝕜 A
inst✝² : Nontrivial 𝕜
inst✝¹ : T2Space 𝕜
inst✝ : ContinuousMul 𝕜
⊢ IsClosed (characterSpace 𝕜 A)
rw [eq_set_map_one_map_mul, Set.setOf_and]
𝕜 : Type u_1
A : Type u_2
inst✝¹⁰ : CommRing 𝕜
inst✝⁹ : NoZeroDivisors 𝕜
inst✝⁸ : TopologicalSpace 𝕜
inst✝⁷ : ContinuousAdd 𝕜
inst✝⁶ : ContinuousConstSMul 𝕜 𝕜
inst✝⁵ : TopologicalSpace A
inst✝⁴ : Semiring A
inst✝³ : Algebra 𝕜 A
inst✝² : Nontrivial 𝕜
inst✝¹ : T2Space 𝕜
inst✝ : ContinuousMul 𝕜
⊢ IsClosed {a | ∀ (x y : A), ↑a (x * y) = ↑a x * ↑a y}
𝕜 : Type u_1
A : Type u_2
inst✝¹⁰ : CommRing 𝕜
inst✝⁹ : NoZeroDivisors 𝕜
inst✝⁸ : TopologicalSpace 𝕜
inst✝⁷ : ContinuousAdd 𝕜
inst✝⁶ : ContinuousConstSMul 𝕜 𝕜
inst✝⁵ : TopologicalSpace A
inst✝⁴ : Semiring A
inst✝³ : Algebra 𝕜 A
inst✝² : Nontrivial 𝕜
inst✝¹ : T2Space 𝕜
inst✝ : ContinuousMul 𝕜
⊢ IsClosed ({a | ↑a 1 = 1} ∩ {a | ∀ (x y : A), ↑a (x * y) = ↑a x * ↑a y})
refine' IsClosed.inter (isClosed_eq (eval_continuous _) continuous_const) _
no goals
𝕜 : Type u_1
A : Type u_2
inst✝¹⁰ : CommRing 𝕜
inst✝⁹ : NoZeroDivisors 𝕜
inst✝⁸ : TopologicalSpace 𝕜
inst✝⁷ : ContinuousAdd 𝕜
inst✝⁶ : ContinuousConstSMul 𝕜 𝕜
inst✝⁵ : TopologicalSpace A
inst✝⁴ : Semiring A
inst✝³ : Algebra 𝕜 A
inst✝² : Nontrivial 𝕜
inst✝¹ : T2Space 𝕜
inst✝ : ContinuousMul 𝕜
⊢ IsClosed {a | ∀ (x y : A), ↑a (x * y) = ↑a x * ↑a y}
simpa only [(union_zero 𝕜 A).symm] using union_zero_isClosed _ _