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closure_eq_of_le {s : set R} {t : subring R} (h₁ : s ⊆ t) (h₂ : t ≤ closure s) : closure s = t
le_antisymm (closure_le.2 h₁) h₂
lemma
subring.closure_eq_of_le
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
closure_induction {s : set R} {p : R → Prop} {x} (h : x ∈ closure s) (Hs : ∀ x ∈ s, p x) (H0 : p 0) (H1 : p 1) (Hadd : ∀ x y, p x → p y → p (x + y)) (Hneg : ∀ (x : R), p x → p (-x)) (Hmul : ∀ x y, p x → p y → p (x * y)) : p x
(@closure_le _ _ _ ⟨p, Hmul, H1, Hadd, H0, Hneg⟩).2 Hs h
lemma
subring.closure_induction
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure" ]
An induction principle for closure membership. If `p` holds for `0`, `1`, and all elements of `s`, and is preserved under addition, negation, and multiplication, then `p` holds for all elements of the closure of `s`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
closure_induction₂ {s : set R} {p : R → R → Prop} {a b : R} (ha : a ∈ closure s) (hb : b ∈ closure s) (Hs : ∀ (x ∈ s) (y ∈ s), p x y) (H0_left : ∀ x, p 0 x) (H0_right : ∀ x, p x 0) (H1_left : ∀ x, p 1 x) (H1_right : ∀ x, p x 1) (Hneg_left : ∀ x y, p x y → p (-x) y) (Hneg_right : ∀ x y, p x y → p x (-y))...
begin refine closure_induction hb _ (H0_right _) (H1_right _) (Hadd_right a) (Hneg_right a) (Hmul_right a), refine closure_induction ha Hs (λ x _, H0_left x) (λ x _, H1_left x) _ _ _, { exact (λ x y H₁ H₂ z zs, Hadd_left x y z (H₁ z zs) (H₂ z zs)) }, { exact (λ x hx z zs, Hneg_left x z (hx z zs)) }, { exa...
lemma
subring.closure_induction₂
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure" ]
An induction principle for closure membership, for predicates with two arguments.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_closure_iff {s : set R} {x} : x ∈ closure s ↔ x ∈ add_subgroup.closure (submonoid.closure s : set R)
⟨λ h, closure_induction h (λ x hx, add_subgroup.subset_closure $ submonoid.subset_closure hx) (add_subgroup.zero_mem _) (add_subgroup.subset_closure ( submonoid.one_mem (submonoid.closure s)) ) (λ x y hx hy, add_subgroup.add_mem _ hx hy ) (λ x hx, add_subgroup.neg_mem _ hx ) (λ x y hx hy, add_subgroup.closure_in...
lemma
subring.mem_closure_iff
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "mem_closure_iff", "mul_zero", "submonoid.closure", "submonoid.closure_induction", "submonoid.one_mem", "submonoid.subset_closure", "subset_closure", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
closure_comm_ring_of_comm {s : set R} (hcomm : ∀ (a ∈ s) (b ∈ s), a * b = b * a) : comm_ring (closure s)
{ mul_comm := λ x y, begin ext, simp only [subring.coe_mul], refine closure_induction₂ x.prop y.prop hcomm (λ x, by simp only [mul_zero, zero_mul]) (λ x, by simp only [mul_zero, zero_mul]) (λ x, by simp only [mul_one, one_mul]) (λ x, by simp only [mul_one, one_mul]) (λ x y hxy, by ...
def
subring.closure_comm_ring_of_comm
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "comm_ring", "mul_assoc", "mul_comm", "mul_neg", "mul_one", "mul_zero", "neg_mul", "one_mul", "subring.coe_mul", "zero_mul" ]
If all elements of `s : set A` commute pairwise, then `closure s` is a commutative ring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_list_of_mem_closure {s : set R} {x : R} (h : x ∈ closure s) : (∃ L : list (list R), (∀ t ∈ L, ∀ y ∈ t, y ∈ s ∨ y = (-1:R)) ∧ (L.map list.prod).sum = x)
add_subgroup.closure_induction (mem_closure_iff.1 h) (λ x hx, let ⟨l, hl, h⟩ :=submonoid.exists_list_of_mem_closure hx in ⟨[l], by simp [h]; clear_aux_decl; tauto!⟩) ⟨[], by simp⟩ (λ x y ⟨l, hl1, hl2⟩ ⟨m, hm1, hm2⟩, ⟨l ++ m, λ t ht, (list.mem_append.1 ht).elim (hl1 t) (hm1 t), by simp [hl2, hm2]⟩) (λ x ...
theorem
subring.exists_list_of_mem_closure
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "list.prod", "submonoid.exists_list_of_mem_closure" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
closure_eq (s : subring R) : closure (s : set R) = s
(subring.gi R).l_u_eq s
lemma
subring.closure_eq
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "subring", "subring.gi" ]
Closure of a subring `S` equals `S`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
closure_empty : closure (∅ : set R) = ⊥
(subring.gi R).gc.l_bot
lemma
subring.closure_empty
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "closure_empty", "subring.gi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
closure_union (s t : set R) : closure (s ∪ t) = closure s ⊔ closure t
(subring.gi R).gc.l_sup
lemma
subring.closure_union
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "closure_union", "subring.gi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
closure_Union {ι} (s : ι → set R) : closure (⋃ i, s i) = ⨆ i, closure (s i)
(subring.gi R).gc.l_supr
lemma
subring.closure_Union
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "closure_Union", "subring.gi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
closure_sUnion (s : set (set R)) : closure (⋃₀ s) = ⨆ t ∈ s, closure t
(subring.gi R).gc.l_Sup
lemma
subring.closure_sUnion
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "subring.gi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_sup (s t : subring R) (f : R →+* S) : (s ⊔ t).map f = s.map f ⊔ t.map f
(gc_map_comap f).l_sup
lemma
subring.map_sup
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_supr {ι : Sort*} (f : R →+* S) (s : ι → subring R) : (supr s).map f = ⨆ i, (s i).map f
(gc_map_comap f).l_supr
lemma
subring.map_supr
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "map_supr", "subring", "supr" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_inf (s t : subring S) (f : R →+* S) : (s ⊓ t).comap f = s.comap f ⊓ t.comap f
(gc_map_comap f).u_inf
lemma
subring.comap_inf
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_infi {ι : Sort*} (f : R →+* S) (s : ι → subring S) : (infi s).comap f = ⨅ i, (s i).comap f
(gc_map_comap f).u_infi
lemma
subring.comap_infi
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "infi", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_bot (f : R →+* S) : (⊥ : subring R).map f = ⊥
(gc_map_comap f).l_bot
lemma
subring.map_bot
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_top (f : R →+* S) : (⊤ : subring S).comap f = ⊤
(gc_map_comap f).u_top
lemma
subring.comap_top
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod (s : subring R) (t : subring S) : subring (R × S)
{ carrier := s ×ˢ t, .. s.to_submonoid.prod t.to_submonoid, .. s.to_add_subgroup.prod t.to_add_subgroup}
def
subring.prod
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
Given `subring`s `s`, `t` of rings `R`, `S` respectively, `s.prod t` is `s ×̂ t` as a subring of `R × S`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_prod (s : subring R) (t : subring S) : (s.prod t : set (R × S)) = s ×ˢ t
rfl
lemma
subring.coe_prod
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_prod {s : subring R} {t : subring S} {p : R × S} : p ∈ s.prod t ↔ p.1 ∈ s ∧ p.2 ∈ t
iff.rfl
lemma
subring.mem_prod
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_mono ⦃s₁ s₂ : subring R⦄ (hs : s₁ ≤ s₂) ⦃t₁ t₂ : subring S⦄ (ht : t₁ ≤ t₂) : s₁.prod t₁ ≤ s₂.prod t₂
set.prod_mono hs ht
lemma
subring.prod_mono
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "set.prod_mono", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_mono_right (s : subring R) : monotone (λ t : subring S, s.prod t)
prod_mono (le_refl s)
lemma
subring.prod_mono_right
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "monotone", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_mono_left (t : subring S) : monotone (λ s : subring R, s.prod t)
λ s₁ s₂ hs, prod_mono hs (le_refl t)
lemma
subring.prod_mono_left
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "monotone", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_top (s : subring R) : s.prod (⊤ : subring S) = s.comap (ring_hom.fst R S)
ext $ λ x, by simp [mem_prod, monoid_hom.coe_fst]
lemma
subring.prod_top
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "monoid_hom.coe_fst", "ring_hom.fst", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
top_prod (s : subring S) : (⊤ : subring R).prod s = s.comap (ring_hom.snd R S)
ext $ λ x, by simp [mem_prod, monoid_hom.coe_snd]
lemma
subring.top_prod
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "monoid_hom.coe_snd", "ring_hom.snd", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
top_prod_top : (⊤ : subring R).prod (⊤ : subring S) = ⊤
(top_prod _).trans $ comap_top _
lemma
subring.top_prod_top
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_equiv (s : subring R) (t : subring S) : s.prod t ≃+* s × t
{ map_mul' := λ x y, rfl, map_add' := λ x y, rfl, .. equiv.set.prod ↑s ↑t }
def
subring.prod_equiv
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "equiv.set.prod", "subring" ]
Product of subrings is isomorphic to their product as rings.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_supr_of_directed {ι} [hι : nonempty ι] {S : ι → subring R} (hS : directed (≤) S) {x : R} : x ∈ (⨆ i, S i) ↔ ∃ i, x ∈ S i
begin refine ⟨_, λ ⟨i, hi⟩, (set_like.le_def.1 $ le_supr S i) hi⟩, let U : subring R := subring.mk' (⋃ i, (S i : set R)) (⨆ i, (S i).to_submonoid) (⨆ i, (S i).to_add_subgroup) (submonoid.coe_supr_of_directed $ hS.mono_comp _ (λ _ _, id)) (add_subgroup.coe_supr_of_directed $ hS.mono_comp _ (λ _ _, id)), ...
lemma
subring.mem_supr_of_directed
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "directed", "le_supr", "submonoid.coe_supr_of_directed", "subring", "subring.mk'", "supr_le" ]
The underlying set of a non-empty directed Sup of subrings is just a union of the subrings. Note that this fails without the directedness assumption (the union of two subrings is typically not a subring)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_supr_of_directed {ι} [hι : nonempty ι] {S : ι → subring R} (hS : directed (≤) S) : ((⨆ i, S i : subring R) : set R) = ⋃ i, ↑(S i)
set.ext $ λ x, by simp [mem_supr_of_directed hS]
lemma
subring.coe_supr_of_directed
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "directed", "set.ext", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_Sup_of_directed_on {S : set (subring R)} (Sne : S.nonempty) (hS : directed_on (≤) S) {x : R} : x ∈ Sup S ↔ ∃ s ∈ S, x ∈ s
begin haveI : nonempty S := Sne.to_subtype, simp only [Sup_eq_supr', mem_supr_of_directed hS.directed_coe, set_coe.exists, subtype.coe_mk] end
lemma
subring.mem_Sup_of_directed_on
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "Sup_eq_supr'", "directed_on", "set_coe.exists", "subring", "subtype.coe_mk" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_Sup_of_directed_on {S : set (subring R)} (Sne : S.nonempty) (hS : directed_on (≤) S) : (↑(Sup S) : set R) = ⋃ s ∈ S, ↑s
set.ext $ λ x, by simp [mem_Sup_of_directed_on Sne hS]
lemma
subring.coe_Sup_of_directed_on
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "directed_on", "set.ext", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_map_equiv {f : R ≃+* S} {K : subring R} {x : S} : x ∈ K.map (f : R →+* S) ↔ f.symm x ∈ K
@set.mem_image_equiv _ _ ↑K f.to_equiv x
lemma
subring.mem_map_equiv
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "set.mem_image_equiv", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_equiv_eq_comap_symm (f : R ≃+* S) (K : subring R) : K.map (f : R →+* S) = K.comap f.symm
set_like.coe_injective (f.to_equiv.image_eq_preimage K)
lemma
subring.map_equiv_eq_comap_symm
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "set_like.coe_injective", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_equiv_eq_map_symm (f : R ≃+* S) (K : subring S) : K.comap (f : R →+* S) = K.map f.symm
(map_equiv_eq_comap_symm f.symm K).symm
lemma
subring.comap_equiv_eq_map_symm
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_restrict (f : R →+* S) : R →+* f.range
f.cod_restrict f.range $ λ x, ⟨x, rfl⟩
def
ring_hom.range_restrict
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[]
Restriction of a ring homomorphism to its range interpreted as a subsemiring. This is the bundled version of `set.range_factorization`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_range_restrict (f : R →+* S) (x : R) : (f.range_restrict x : S) = f x
rfl
lemma
ring_hom.coe_range_restrict
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_restrict_surjective (f : R →+* S) : function.surjective f.range_restrict
λ ⟨y, hy⟩, let ⟨x, hx⟩ := mem_range.mp hy in ⟨x, subtype.ext hx⟩
lemma
ring_hom.range_restrict_surjective
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_top_iff_surjective {f : R →+* S} : f.range = (⊤ : subring S) ↔ function.surjective f
set_like.ext'_iff.trans $ iff.trans (by rw [coe_range, coe_top]) set.range_iff_surjective
lemma
ring_hom.range_top_iff_surjective
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "set.range_iff_surjective", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_top_of_surjective (f : R →+* S) (hf : function.surjective f) : f.range = (⊤ : subring S)
range_top_iff_surjective.2 hf
lemma
ring_hom.range_top_of_surjective
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
The range of a surjective ring homomorphism is the whole of the codomain.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_locus (f g : R →+* S) : subring R
{ carrier := {x | f x = g x}, .. (f : R →* S).eq_mlocus g, .. (f : R →+ S).eq_locus g }
def
ring_hom.eq_locus
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
The subring of elements `x : R` such that `f x = g x`, i.e., the equalizer of f and g as a subring of R
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_locus_same (f : R →+* S) : f.eq_locus f = ⊤
set_like.ext $ λ _, eq_self_iff_true _
lemma
ring_hom.eq_locus_same
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "set_like.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_on_set_closure {f g : R →+* S} {s : set R} (h : set.eq_on f g s) : set.eq_on f g (closure s)
show closure s ≤ f.eq_locus g, from closure_le.2 h
lemma
ring_hom.eq_on_set_closure
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "set.eq_on" ]
If two ring homomorphisms are equal on a set, then they are equal on its subring closure.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_of_eq_on_set_top {f g : R →+* S} (h : set.eq_on f g (⊤ : subring R)) : f = g
ext $ λ x, h trivial
lemma
ring_hom.eq_of_eq_on_set_top
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "set.eq_on", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_of_eq_on_set_dense {s : set R} (hs : closure s = ⊤) {f g : R →+* S} (h : s.eq_on f g) : f = g
eq_of_eq_on_set_top $ hs ▸ eq_on_set_closure h
lemma
ring_hom.eq_of_eq_on_set_dense
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
closure_preimage_le (f : R →+* S) (s : set S) : closure (f ⁻¹' s) ≤ (closure s).comap f
closure_le.2 $ λ x hx, set_like.mem_coe.2 $ mem_comap.2 $ subset_closure hx
lemma
ring_hom.closure_preimage_le
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "subset_closure" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_closure (f : R →+* S) (s : set R) : (closure s).map f = closure (f '' s)
le_antisymm (map_le_iff_le_comap.2 $ le_trans (closure_mono $ set.subset_preimage_image _ _) (closure_preimage_le _ _)) (closure_le.2 $ set.image_subset _ subset_closure)
lemma
ring_hom.map_closure
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "closure_mono", "set.image_subset", "set.subset_preimage_image", "subset_closure" ]
The image under a ring homomorphism of the subring generated by a set equals the subring generated by the image of the set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inclusion {S T : subring R} (h : S ≤ T) : S →+* T
S.subtype.cod_restrict _ (λ x, h x.2)
def
subring.inclusion
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "subring" ]
The ring homomorphism associated to an inclusion of subrings.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_subtype (s : subring R) : s.subtype.range = s
set_like.coe_injective $ (coe_srange _).trans subtype.range_coe
lemma
subring.range_subtype
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "set_like.coe_injective", "subring", "subtype.range_coe" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_fst : (fst R S).srange = ⊤
(fst R S).srange_top_of_surjective $ prod.fst_surjective
lemma
subring.range_fst
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "prod.fst_surjective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_snd : (snd R S).srange = ⊤
(snd R S).srange_top_of_surjective $ prod.snd_surjective
lemma
subring.range_snd
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "prod.snd_surjective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_bot_sup_bot_prod (s : subring R) (t : subring S) : (s.prod ⊥) ⊔ (prod ⊥ t) = s.prod t
le_antisymm (sup_le (prod_mono_right s bot_le) (prod_mono_left t bot_le)) $ assume p hp, prod.fst_mul_snd p ▸ mul_mem ((le_sup_left : s.prod ⊥ ≤ s.prod ⊥ ⊔ prod ⊥ t) ⟨hp.1, set_like.mem_coe.2 $ one_mem ⊥⟩) ((le_sup_right : prod ⊥ t ≤ s.prod ⊥ ⊔ prod ⊥ t) ⟨set_like.mem_coe.2 $ one_mem ⊥, hp.2⟩)
lemma
subring.prod_bot_sup_bot_prod
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "bot_le", "le_sup_left", "le_sup_right", "prod.fst_mul_snd", "subring", "sup_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subring_congr (h : s = t) : s ≃+* t
{ map_mul' := λ _ _, rfl, map_add' := λ _ _, rfl, ..equiv.set_congr $ congr_arg _ h }
def
ring_equiv.subring_congr
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "equiv.set_congr" ]
Makes the identity isomorphism from a proof two subrings of a multiplicative monoid are equal.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_left_inverse {g : S → R} {f : R →+* S} (h : function.left_inverse g f) : R ≃+* f.range
{ to_fun := λ x, f.range_restrict x, inv_fun := λ x, (g ∘ f.range.subtype) x, left_inv := h, right_inv := λ x, subtype.ext $ let ⟨x', hx'⟩ := ring_hom.mem_range.mp x.prop in show f (g x) = x, by rw [←hx', h x'], ..f.range_restrict }
def
ring_equiv.of_left_inverse
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "inv_fun", "subtype.ext" ]
Restrict a ring homomorphism with a left inverse to a ring isomorphism to its `ring_hom.range`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_left_inverse_apply {g : S → R} {f : R →+* S} (h : function.left_inverse g f) (x : R) : ↑(of_left_inverse h x) = f x
rfl
lemma
ring_equiv.of_left_inverse_apply
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_left_inverse_symm_apply {g : S → R} {f : R →+* S} (h : function.left_inverse g f) (x : f.range) : (of_left_inverse h).symm x = g x
rfl
lemma
ring_equiv.of_left_inverse_symm_apply
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subring_map (e : R ≃+* S) : s ≃+* s.map e.to_ring_hom
e.subsemiring_map s.to_subsemiring
def
ring_equiv.subring_map
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[]
Given an equivalence `e : R ≃+* S` of rings and a subring `s` of `R`, `subring_equiv_map e s` is the induced equivalence between `s` and `s.map e`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
in_closure.rec_on {C : R → Prop} {x : R} (hx : x ∈ closure s) (h1 : C 1) (hneg1 : C (-1)) (hs : ∀ z ∈ s, ∀ n, C n → C (z * n)) (ha : ∀ {x y}, C x → C y → C (x + y)) : C x
begin have h0 : C 0 := add_neg_self (1:R) ▸ ha h1 hneg1, rcases exists_list_of_mem_closure hx with ⟨L, HL, rfl⟩, clear hx, induction L with hd tl ih, { exact h0 }, rw list.forall_mem_cons at HL, suffices : C (list.prod hd), { rw [list.map_cons, list.sum_cons], exact ha this (ih HL.2) }, replace HL := ...
theorem
subring.in_closure.rec_on
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "closure", "ih", "list.forall_mem_cons", "list.forall_mem_nil", "list.prod", "list.prod_cons", "neg_mul_eq_mul_neg", "neg_one_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_subgroup.int_mul_mem {G : add_subgroup R} (k : ℤ) {g : R} (h : g ∈ G) : (k : R) * g ∈ G
by { convert add_subgroup.zsmul_mem G h k, simp }
lemma
add_subgroup.int_mul_mem
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "add_subgroup" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_def [has_smul R α] {S : subring R} (g : S) (m : α) : g • m = (g : R) • m
rfl
lemma
subring.smul_def
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "has_smul", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_comm_class_left [has_smul R β] [has_smul α β] [smul_comm_class R α β] (S : subring R) : smul_comm_class S α β
S.to_subsemiring.smul_comm_class_left
instance
subring.smul_comm_class_left
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "has_smul", "smul_comm_class", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_comm_class_right [has_smul α β] [has_smul R β] [smul_comm_class α R β] (S : subring R) : smul_comm_class α S β
S.to_subsemiring.smul_comm_class_right
instance
subring.smul_comm_class_right
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "has_smul", "smul_comm_class", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
center.smul_comm_class_left : smul_comm_class (center R) R R
subsemiring.center.smul_comm_class_left
instance
subring.center.smul_comm_class_left
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "smul_comm_class", "subsemiring.center.smul_comm_class_left" ]
The center of a semiring acts commutatively on that semiring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
center.smul_comm_class_right : smul_comm_class R (center R) R
subsemiring.center.smul_comm_class_right
instance
subring.center.smul_comm_class_right
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "smul_comm_class", "subsemiring.center.smul_comm_class_right" ]
The center of a semiring acts commutatively on that semiring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
units.pos_subgroup (R : Type*) [linear_ordered_semiring R] : subgroup Rˣ
{ carrier := {x | (0 : R) < x}, inv_mem' := λ x, units.inv_pos.mpr, ..(pos_submonoid R).comap (units.coe_hom R)}
def
units.pos_subgroup
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "linear_ordered_semiring", "pos_submonoid", "subgroup", "units.coe_hom" ]
The subgroup of positive units of a linear ordered semiring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
units.mem_pos_subgroup {R : Type*} [linear_ordered_semiring R] (u : Rˣ) : u ∈ units.pos_subgroup R ↔ (0 : R) < u
iff.rfl
lemma
units.mem_pos_subgroup
ring_theory.subring
src/ring_theory/subring/basic.lean
[ "group_theory.subgroup.basic", "ring_theory.subsemiring.basic" ]
[ "linear_ordered_semiring", "units.pos_subgroup" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pointwise_mul_action : mul_action M (subring R)
{ smul := λ a S, S.map (mul_semiring_action.to_ring_hom _ _ a), one_smul := λ S, (congr_arg (λ f, S.map f) (ring_hom.ext $ by exact one_smul M)).trans S.map_id, mul_smul := λ a₁ a₂ S, (congr_arg (λ f, S.map f) (ring_hom.ext $ by exact mul_smul _ _)).trans (S.map_map _ _).symm }
def
subring.pointwise_mul_action
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "mul_action", "mul_semiring_action.to_ring_hom", "one_smul", "ring_hom.ext", "subring" ]
The action on a subring corresponding to applying the action to every element. This is available as an instance in the `pointwise` locale.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pointwise_smul_def {a : M} (S : subring R) : a • S = S.map (mul_semiring_action.to_ring_hom _ _ a)
rfl
lemma
subring.pointwise_smul_def
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "mul_semiring_action.to_ring_hom", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_pointwise_smul (m : M) (S : subring R) : ↑(m • S) = m • (S : set R)
rfl
lemma
subring.coe_pointwise_smul
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pointwise_smul_to_add_subgroup (m : M) (S : subring R) : (m • S).to_add_subgroup = m • S.to_add_subgroup
rfl
lemma
subring.pointwise_smul_to_add_subgroup
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pointwise_smul_to_subsemiring (m : M) (S : subring R) : (m • S).to_subsemiring = m • S.to_subsemiring
rfl
lemma
subring.pointwise_smul_to_subsemiring
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_mem_pointwise_smul (m : M) (r : R) (S : subring R) : r ∈ S → m • r ∈ m • S
(set.smul_mem_smul_set : _ → _ ∈ m • (S : set R))
lemma
subring.smul_mem_pointwise_smul
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "set.smul_mem_smul_set", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_smul_pointwise_iff_exists (m : M) (r : R) (S : subring R) : r ∈ m • S ↔ ∃ (s : R), s ∈ S ∧ m • s = r
(set.mem_smul_set : r ∈ m • (S : set R) ↔ _)
lemma
subring.mem_smul_pointwise_iff_exists
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "set.mem_smul_set", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_bot (a : M) : a • (⊥ : subring R) = ⊥
map_bot _
lemma
subring.smul_bot
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_sup (a : M) (S T : subring R) : a • (S ⊔ T) = a • S ⊔ a • T
map_sup _ _ _
lemma
subring.smul_sup
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_closure (a : M) (s : set R) : a • closure s = closure (a • s)
ring_hom.map_closure _ _
lemma
subring.smul_closure
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "closure", "ring_hom.map_closure" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pointwise_central_scalar [mul_semiring_action Mᵐᵒᵖ R] [is_central_scalar M R] : is_central_scalar M (subring R)
⟨λ a S, congr_arg (λ f, S.map f) $ ring_hom.ext $ by exact op_smul_eq_smul _⟩
instance
subring.pointwise_central_scalar
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "is_central_scalar", "mul_semiring_action", "ring_hom.ext", "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_mem_pointwise_smul_iff {a : M} {S : subring R} {x : R} : a • x ∈ a • S ↔ x ∈ S
smul_mem_smul_set_iff
lemma
subring.smul_mem_pointwise_smul_iff
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_pointwise_smul_iff_inv_smul_mem {a : M} {S : subring R} {x : R} : x ∈ a • S ↔ a⁻¹ • x ∈ S
mem_smul_set_iff_inv_smul_mem
lemma
subring.mem_pointwise_smul_iff_inv_smul_mem
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_inv_pointwise_smul_iff {a : M} {S : subring R} {x : R} : x ∈ a⁻¹ • S ↔ a • x ∈ S
mem_inv_smul_set_iff
lemma
subring.mem_inv_pointwise_smul_iff
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pointwise_smul_le_pointwise_smul_iff {a : M} {S T : subring R} : a • S ≤ a • T ↔ S ≤ T
set_smul_subset_set_smul_iff
lemma
subring.pointwise_smul_le_pointwise_smul_iff
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pointwise_smul_subset_iff {a : M} {S T : subring R} : a • S ≤ T ↔ S ≤ a⁻¹ • T
set_smul_subset_iff
lemma
subring.pointwise_smul_subset_iff
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subset_pointwise_smul_iff {a : M} {S T : subring R} : S ≤ a • T ↔ a⁻¹ • S ≤ T
subset_set_smul_iff
lemma
subring.subset_pointwise_smul_iff
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_mem_pointwise_smul_iff₀ {a : M} (ha : a ≠ 0) (S : subring R) (x : R) : a • x ∈ a • S ↔ x ∈ S
smul_mem_smul_set_iff₀ ha (S : set R) x
lemma
subring.smul_mem_pointwise_smul_iff₀
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_pointwise_smul_iff_inv_smul_mem₀ {a : M} (ha : a ≠ 0) (S : subring R) (x : R) : x ∈ a • S ↔ a⁻¹ • x ∈ S
mem_smul_set_iff_inv_smul_mem₀ ha (S : set R) x
lemma
subring.mem_pointwise_smul_iff_inv_smul_mem₀
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_inv_pointwise_smul_iff₀ {a : M} (ha : a ≠ 0) (S : subring R) (x : R) : x ∈ a⁻¹ • S ↔ a • x ∈ S
mem_inv_smul_set_iff₀ ha (S : set R) x
lemma
subring.mem_inv_pointwise_smul_iff₀
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pointwise_smul_le_pointwise_smul_iff₀ {a : M} (ha : a ≠ 0) {S T : subring R} : a • S ≤ a • T ↔ S ≤ T
set_smul_subset_set_smul_iff₀ ha
lemma
subring.pointwise_smul_le_pointwise_smul_iff₀
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pointwise_smul_le_iff₀ {a : M} (ha : a ≠ 0) {S T : subring R} : a • S ≤ T ↔ S ≤ a⁻¹ • T
set_smul_subset_iff₀ ha
lemma
subring.pointwise_smul_le_iff₀
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_pointwise_smul_iff₀ {a : M} (ha : a ≠ 0) {S T : subring R} : S ≤ a • T ↔ a⁻¹ • S ≤ T
subset_set_smul_iff₀ ha
lemma
subring.le_pointwise_smul_iff₀
ring_theory.subring
src/ring_theory/subring/pointwise.lean
[ "ring_theory.subring.basic", "group_theory.subgroup.pointwise", "ring_theory.subsemiring.pointwise", "data.set.pointwise.basic" ]
[ "subring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_submonoid_with_one_class (S : Type*) (R : Type*) [add_monoid_with_one R] [set_like S R] extends add_submonoid_class S R, one_mem_class S R : Prop
class
add_submonoid_with_one_class
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "add_monoid_with_one", "add_submonoid_class", "one_mem_class", "set_like" ]
`add_submonoid_with_one_class S R` says `S` is a type of subsets `s ≤ R` that contain `0`, `1`, and are closed under `(+)`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nat_cast_mem [add_submonoid_with_one_class S R] (n : ℕ) : (n : R) ∈ s
by induction n; simp [zero_mem, add_mem, one_mem, *]
lemma
nat_cast_mem
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "add_submonoid_with_one_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_submonoid_with_one_class.to_add_monoid_with_one [add_submonoid_with_one_class S R] : add_monoid_with_one s
{ one := ⟨_, one_mem s⟩, nat_cast := λ n, ⟨n, nat_cast_mem s n⟩, nat_cast_zero := subtype.ext nat.cast_zero, nat_cast_succ := λ n, subtype.ext (nat.cast_succ _), .. add_submonoid_class.to_add_monoid s }
instance
add_submonoid_with_one_class.to_add_monoid_with_one
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "add_monoid_with_one", "add_submonoid_with_one_class", "nat.cast_succ", "nat.cast_zero", "nat_cast_mem", "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subsemiring_class (S : Type*) (R : Type u) [non_assoc_semiring R] [set_like S R] extends submonoid_class S R, add_submonoid_class S R : Prop
class
subsemiring_class
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "add_submonoid_class", "non_assoc_semiring", "set_like", "submonoid_class" ]
`subsemiring_class S R` states that `S` is a type of subsets `s ⊆ R` that are both a multiplicative and an additive submonoid.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subsemiring_class.add_submonoid_with_one_class (S : Type*) (R : Type u) [non_assoc_semiring R] [set_like S R] [h : subsemiring_class S R] : add_submonoid_with_one_class S R
{ .. h }
instance
subsemiring_class.add_submonoid_with_one_class
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "add_submonoid_with_one_class", "non_assoc_semiring", "set_like", "subsemiring_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_nat_mem (n : ℕ) : (n : R) ∈ s
by { rw ← nsmul_one, exact nsmul_mem (one_mem _) _ }
lemma
coe_nat_mem
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "nsmul_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_non_assoc_semiring : non_assoc_semiring s
subtype.coe_injective.non_assoc_semiring coe rfl rfl (λ _ _, rfl) (λ _ _, rfl) (λ _ _, rfl) (λ _, rfl)
instance
subsemiring_class.to_non_assoc_semiring
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "non_assoc_semiring" ]
A subsemiring of a `non_assoc_semiring` inherits a `non_assoc_semiring` structure
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nontrivial [nontrivial R] : nontrivial s
nontrivial_of_ne 0 1 $ λ H, zero_ne_one (congr_arg subtype.val H)
instance
subsemiring_class.nontrivial
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "nontrivial", "nontrivial_of_ne", "zero_ne_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
no_zero_divisors [no_zero_divisors R] : no_zero_divisors s
{ eq_zero_or_eq_zero_of_mul_eq_zero := λ x y h, or.cases_on (eq_zero_or_eq_zero_of_mul_eq_zero $ subtype.ext_iff.mp h) (λ h, or.inl $ subtype.eq h) (λ h, or.inr $ subtype.eq h) }
instance
subsemiring_class.no_zero_divisors
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "no_zero_divisors" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subtype : s →+* R
{ to_fun := coe, .. submonoid_class.subtype s, .. add_submonoid_class.subtype s }
def
subsemiring_class.subtype
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "submonoid_class.subtype" ]
The natural ring hom from a subsemiring of semiring `R` to `R`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_semiring {R} [semiring R] [set_like S R] [subsemiring_class S R] : semiring s
subtype.coe_injective.semiring coe rfl rfl (λ _ _, rfl) (λ _ _, rfl) (λ _ _, rfl) (λ _ _, rfl) (λ _, rfl)
instance
subsemiring_class.to_semiring
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "semiring", "set_like", "subsemiring_class" ]
A subsemiring of a `semiring` is a `semiring`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_pow {R} [semiring R] [set_like S R] [subsemiring_class S R] (x : s) (n : ℕ) : ((x^n : s) : R) = (x^n : R)
begin induction n with n ih, { simp, }, { simp [pow_succ, ih], }, end
lemma
subsemiring_class.coe_pow
ring_theory.subsemiring
src/ring_theory/subsemiring/basic.lean
[ "algebra.module.basic", "algebra.ring.equiv", "algebra.ring.prod", "algebra.order.ring.inj_surj", "algebra.group_ring_action.subobjects", "data.set.finite", "group_theory.submonoid.centralizer", "group_theory.submonoid.membership" ]
[ "ih", "pow_succ", "semiring", "set_like", "subsemiring_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83