Theorem: NonUnitalStarSubalgebra.mem_centralizer_iff
File: Mathlib/Algebra/Star/NonUnitalSubalgebra.lean

Proof steps:
state_before: F : Type v'
R' : Type u'
R : Type u
A : Type v
B : Type w
C : Type w'
inst✝¹⁶ : CommSemiring R
inst✝¹⁵ : StarRing R
inst✝¹⁴ : NonUnitalSemiring A
inst✝¹³ : StarRing A
inst✝¹² : Module R A
inst✝¹¹ : IsScalarTower R A A
inst✝¹⁰ : SMulCommClass R A A
inst✝⁹ : StarModule R A
inst✝⁸ : NonUnitalSemiring B
inst✝⁷ : StarRing B
inst✝⁶ : Module R B
inst✝⁵ : IsScalarTower R B B
inst✝⁴ : SMulCommClass R B B
inst✝³ : StarModule R B
inst✝² : FunLike F A B
inst✝¹ : NonUnitalAlgHomClass F R A B
inst✝ : NonUnitalStarAlgHomClass F R A B
S : NonUnitalStarSubalgebra R A
s : Set A
z : A
⊢ z ∈ centralizer R s ↔ ∀ g ∈ s, g * z = z * g ∧ star g * z = z * star g
state_after: F : Type v'
R' : Type u'
R : Type u
A : Type v
B : Type w
C : Type w'
inst✝¹⁶ : CommSemiring R
inst✝¹⁵ : StarRing R
inst✝¹⁴ : NonUnitalSemiring A
inst✝¹³ : StarRing A
inst✝¹² : Module R A
inst✝¹¹ : IsScalarTower R A A
inst✝¹⁰ : SMulCommClass R A A
inst✝⁹ : StarModule R A
inst✝⁸ : NonUnitalSemiring B
inst✝⁷ : StarRing B
inst✝⁶ : Module R B
inst✝⁵ : IsScalarTower R B B
inst✝⁴ : SMulCommClass R B B
inst✝³ : StarModule R B
inst✝² : FunLike F A B
inst✝¹ : NonUnitalAlgHomClass F R A B
inst✝ : NonUnitalStarAlgHomClass F R A B
S : NonUnitalStarSubalgebra R A
s : Set A
z : A
⊢ (∀ g ∈ s ∪ star s, g * z = z * g) ↔ ∀ g ∈ s, g * z = z * g ∧ star g * z = z * star g
tactic: show (∀ g ∈ s ∪ star s, g * z = z * g) ↔ ∀ g ∈ s, g * z = z * g ∧ star g * z = z * star g
state_before: F : Type v'
R' : Type u'
R : Type u
A : Type v
B : Type w
C : Type w'
inst✝¹⁶ : CommSemiring R
inst✝¹⁵ : StarRing R
inst✝¹⁴ : NonUnitalSemiring A
inst✝¹³ : StarRing A
inst✝¹² : Module R A
inst✝¹¹ : IsScalarTower R A A
inst✝¹⁰ : SMulCommClass R A A
inst✝⁹ : StarModule R A
inst✝⁸ : NonUnitalSemiring B
inst✝⁷ : StarRing B
inst✝⁶ : Module R B
inst✝⁵ : IsScalarTower R B B
inst✝⁴ : SMulCommClass R B B
inst✝³ : StarModule R B
inst✝² : FunLike F A B
inst✝¹ : NonUnitalAlgHomClass F R A B
inst✝ : NonUnitalStarAlgHomClass F R A B
S : NonUnitalStarSubalgebra R A
s : Set A
z : A
⊢ (∀ g ∈ s ∪ star s, g * z = z * g) ↔ ∀ g ∈ s, g * z = z * g ∧ star g * z = z * star g
state_after: F : Type v'
R' : Type u'
R : Type u
A : Type v
B : Type w
C : Type w'
inst✝¹⁶ : CommSemiring R
inst✝¹⁵ : StarRing R
inst✝¹⁴ : NonUnitalSemiring A
inst✝¹³ : StarRing A
inst✝¹² : Module R A
inst✝¹¹ : IsScalarTower R A A
inst✝¹⁰ : SMulCommClass R A A
inst✝⁹ : StarModule R A
inst✝⁸ : NonUnitalSemiring B
inst✝⁷ : StarRing B
inst✝⁶ : Module R B
inst✝⁵ : IsScalarTower R B B
inst✝⁴ : SMulCommClass R B B
inst✝³ : StarModule R B
inst✝² : FunLike F A B
inst✝¹ : NonUnitalAlgHomClass F R A B
inst✝ : NonUnitalStarAlgHomClass F R A B
S : NonUnitalStarSubalgebra R A
s : Set A
z : A
⊢ (∀ x ∈ s, x * z = z * x) → ((∀ x ∈ star s, x * z = z * x) ↔ ∀ x ∈ s, star x * z = z * star x)
tactic: simp only [Set.mem_union, or_imp, forall_and, and_congr_right_iff]
state_before: F : Type v'
R' : Type u'
R : Type u
A : Type v
B : Type w
C : Type w'
inst✝¹⁶ : CommSemiring R
inst✝¹⁵ : StarRing R
inst✝¹⁴ : NonUnitalSemiring A
inst✝¹³ : StarRing A
inst✝¹² : Module R A
inst✝¹¹ : IsScalarTower R A A
inst✝¹⁰ : SMulCommClass R A A
inst✝⁹ : StarModule R A
inst✝⁸ : NonUnitalSemiring B
inst✝⁷ : StarRing B
inst✝⁶ : Module R B
inst✝⁵ : IsScalarTower R B B
inst✝⁴ : SMulCommClass R B B
inst✝³ : StarModule R B
inst✝² : FunLike F A B
inst✝¹ : NonUnitalAlgHomClass F R A B
inst✝ : NonUnitalStarAlgHomClass F R A B
S : NonUnitalStarSubalgebra R A
s : Set A
z : A
⊢ (∀ x ∈ s, x * z = z * x) → ((∀ x ∈ star s, x * z = z * x) ↔ ∀ x ∈ s, star x * z = z * star x)
state_after: no goals
tactic: exact fun _ =>
    ⟨fun hz a ha => hz _ (Set.star_mem_star.mpr ha), fun hz a ha => star_star a ▸ hz _ ha⟩