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[Merged by Bors] - chore(*/centralizer): add forgotten to_additives #19168

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[Merged by Bors] - chore(*/centralizer): add forgotten to_additives #19168

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5 changes: 3 additions & 2 deletions src/group_theory/subgroup/basic.lean
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Expand Up @@ -1604,12 +1604,13 @@ set_like.ext' (set.centralizer_univ G)
@[to_additive] lemma le_centralizer_iff : H ≤ K.centralizer ↔ K ≤ H.centralizer :=
⟨λ h x hx y hy, (h hy x hx).symm, λ h x hx y hy, (h hy x hx).symm⟩

lemma center_le_centralizer (s) : center G ≤ centralizer s := set.center_subset_centralizer s
@[to_additive] lemma center_le_centralizer (s) : center G ≤ centralizer s :=
set.center_subset_centralizer s

@[to_additive] lemma centralizer_le (h : H ≤ K) : centralizer K ≤ centralizer H :=
submonoid.centralizer_le h

@[simp] lemma centralizer_eq_top_iff_subset {s} : centralizer s = ⊤ ↔ s ≤ center G :=
@[simp, to_additive] lemma centralizer_eq_top_iff_subset {s} : centralizer s = ⊤ ↔ s ≤ center G :=
set_like.ext'_iff.trans set.centralizer_eq_top_iff_subset

@[to_additive] instance subgroup.centralizer.characteristic [hH : H.characteristic] :
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6 changes: 4 additions & 2 deletions src/group_theory/submonoid/centralizer.lean
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Expand Up @@ -50,7 +50,8 @@ variables {S}
@[to_additive] lemma mem_centralizer_iff {z : M} : z ∈ centralizer S ↔ ∀ g ∈ S, g * z = z * g :=
iff.rfl

lemma center_le_centralizer (s) : center M ≤ centralizer s := s.center_subset_centralizer
@[to_additive] lemma center_le_centralizer (s) : center M ≤ centralizer s :=
s.center_subset_centralizer

@[to_additive] instance decidable_mem_centralizer (a) [decidable $ ∀ b ∈ S, b * a = a * b] :
decidable (a ∈ centralizer S) :=
Expand All @@ -60,7 +61,8 @@ decidable_of_iff' _ mem_centralizer_iff
lemma centralizer_le (h : S ⊆ T) : centralizer T ≤ centralizer S :=
set.centralizer_subset h

@[simp] lemma centralizer_eq_top_iff_subset {s : set M} : centralizer s = ⊤ ↔ s ⊆ center M :=
@[simp, to_additive] lemma centralizer_eq_top_iff_subset {s : set M} :
centralizer s = ⊤ ↔ s ⊆ center M :=
set_like.ext'_iff.trans set.centralizer_eq_top_iff_subset

variables (M)
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8 changes: 6 additions & 2 deletions src/group_theory/subsemigroup/centralizer.lean
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Expand Up @@ -100,10 +100,12 @@ end
lemma centralizer_subset [has_mul M] (h : S ⊆ T) : centralizer T ⊆ centralizer S :=
λ t ht s hs, ht s (h hs)

@[to_additive add_center_subset_add_centralizer]
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@urkud urkud Jun 9, 2023 •
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What name does to_additive generate here? Why does it generate a wrong name here and generates a correct name for center_le_centralizer?

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It gives the same name. I'm not sure why later on it's not an issue, maybe when a section closes the database for to_additive updates, or the like. I think it's the same in lean4

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and generates a correct name for center_le_centralizer?

Because the correct additivized name for subgroup.center_le_centralizer is add_subsemigroup.center_le_centralizer, there's no need to replace centralizer with add_centralizer.

Only the set lemmas need these renames.

lemma center_subset_centralizer [has_mul M] (S : set M) : set.center M ⊆ S.centralizer :=
λ x hx m _, hx m

@[simp] lemma centralizer_eq_top_iff_subset {s : set M} [has_mul M] :
@[simp, to_additive add_centralizer_eq_top_iff_subset]
lemma centralizer_eq_top_iff_subset {s : set M} [has_mul M] :
centralizer s = set.univ ↔ s ⊆ center M :=
eq_top_iff.trans $ ⟨λ h x hx g, (h trivial _ hx).symm,
λ h x _ m hm, (h hm x).symm⟩
Expand Down Expand Up @@ -144,13 +146,15 @@ iff.rfl
decidable (a ∈ centralizer S) :=
decidable_of_iff' _ mem_centralizer_iff

@[to_additive]
lemma center_le_centralizer (S) : center M ≤ centralizer S := S.center_subset_centralizer

@[to_additive]
lemma centralizer_le (h : S ⊆ T) : centralizer T ≤ centralizer S :=
set.centralizer_subset h

@[simp] lemma centralizer_eq_top_iff_subset {s : set M} : centralizer s = ⊤ ↔ s ⊆ center M :=
@[simp, to_additive]
lemma centralizer_eq_top_iff_subset {s : set M} : centralizer s = ⊤ ↔ s ⊆ center M :=
set_like.ext'_iff.trans set.centralizer_eq_top_iff_subset

variables (M)
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