statement
stringlengths
1
2.88k
proof
stringlengths
0
13.9k
type
stringclasses
10 values
symbolic_name
stringlengths
1
131
library
stringclasses
417 values
filename
stringlengths
17
80
imports
listlengths
0
16
deps
listlengths
0
64
docstring
stringlengths
0
10.2k
source_url
stringclasses
1 value
commit
stringclasses
1 value
to_subalgebra_to_submodule (p : submodule R A) (h_one h_mul) : (p.to_subalgebra h_one h_mul).to_submodule = p
set_like.coe_injective rfl
lemma
submodule.to_subalgebra_to_submodule
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set_like.coe_injective", "submodule" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.subalgebra.to_submodule_to_subalgebra (S : subalgebra R A) : S.to_submodule.to_subalgebra S.one_mem (λ _ _, S.mul_mem) = S
set_like.coe_injective rfl
lemma
subalgebra.to_submodule_to_subalgebra
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set_like.coe_injective", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range (φ : A →ₐ[R] B) : subalgebra R B
{ algebra_map_mem' := λ r, ⟨algebra_map R A r, φ.commutes r⟩, .. φ.to_ring_hom.srange }
def
alg_hom.range
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
Range of an `alg_hom` as a subalgebra.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_range (φ : A →ₐ[R] B) {y : B} : y ∈ φ.range ↔ ∃ x, φ x = y
ring_hom.mem_srange
lemma
alg_hom.mem_range
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "ring_hom.mem_srange" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_range_self (φ : A →ₐ[R] B) (x : A) : φ x ∈ φ.range
φ.mem_range.2 ⟨x, rfl⟩
theorem
alg_hom.mem_range_self
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_range (φ : A →ₐ[R] B) : (φ.range : set B) = set.range φ
by { ext, rw [set_like.mem_coe, mem_range], refl }
lemma
alg_hom.coe_range
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.range", "set_like.mem_coe" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_comp (f : A →ₐ[R] B) (g : B →ₐ[R] C) : (g.comp f).range = f.range.map g
set_like.coe_injective (set.range_comp g f)
theorem
alg_hom.range_comp
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.range_comp", "set_like.coe_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_comp_le_range (f : A →ₐ[R] B) (g : B →ₐ[R] C) : (g.comp f).range ≤ g.range
set_like.coe_mono (set.range_comp_subset_range f g)
theorem
alg_hom.range_comp_le_range
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.range_comp_subset_range", "set_like.coe_mono" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cod_restrict (f : A →ₐ[R] B) (S : subalgebra R B) (hf : ∀ x, f x ∈ S) : A →ₐ[R] S
{ commutes' := λ r, subtype.eq $ f.commutes r, .. ring_hom.cod_restrict (f : A →+* B) S hf }
def
alg_hom.cod_restrict
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "ring_hom.cod_restrict", "subalgebra" ]
Restrict the codomain of an algebra homomorphism.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
val_comp_cod_restrict (f : A →ₐ[R] B) (S : subalgebra R B) (hf : ∀ x, f x ∈ S) : S.val.comp (f.cod_restrict S hf) = f
alg_hom.ext $ λ _, rfl
lemma
alg_hom.val_comp_cod_restrict
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_hom.ext", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_cod_restrict (f : A →ₐ[R] B) (S : subalgebra R B) (hf : ∀ x, f x ∈ S) (x : A) : ↑(f.cod_restrict S hf x) = f x
rfl
lemma
alg_hom.coe_cod_restrict
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
injective_cod_restrict (f : A →ₐ[R] B) (S : subalgebra R B) (hf : ∀ x, f x ∈ S) : function.injective (f.cod_restrict S hf) ↔ function.injective f
⟨λ H x y hxy, H $ subtype.eq hxy, λ H x y hxy, H (congr_arg subtype.val hxy : _)⟩
theorem
alg_hom.injective_cod_restrict
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_restrict (f : A →ₐ[R] B) : A →ₐ[R] f.range
f.cod_restrict f.range f.mem_range_self
def
alg_hom.range_restrict
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[]
Restrict the codomain of a alg_hom `f` to `f.range`. This is the bundled version of `set.range_factorization`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equalizer (ϕ ψ : A →ₐ[R] B) : subalgebra R A
{ carrier := {a | ϕ a = ψ a}, add_mem' := λ x y (hx : ϕ x = ψ x) (hy : ϕ y = ψ y), by rw [set.mem_set_of_eq, ϕ.map_add, ψ.map_add, hx, hy], mul_mem' := λ x y (hx : ϕ x = ψ x) (hy : ϕ y = ψ y), by rw [set.mem_set_of_eq, ϕ.map_mul, ψ.map_mul, hx, hy], algebra_map_mem' := λ x, by rw [set.mem_set_of_eq, a...
def
alg_hom.equalizer
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_hom.commutes", "subalgebra" ]
The equalizer of two R-algebra homomorphisms
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_equalizer (ϕ ψ : A →ₐ[R] B) (x : A) : x ∈ ϕ.equalizer ψ ↔ ϕ x = ψ x
iff.rfl
lemma
alg_hom.mem_equalizer
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fintype_range [fintype A] [decidable_eq B] (φ : A →ₐ[R] B) : fintype φ.range
set.fintype_range φ
instance
alg_hom.fintype_range
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "fintype", "set.fintype_range" ]
The range of a morphism of algebras is a fintype, if the domain is a fintype. Note that this instance can cause a diamond with `subtype.fintype` if `B` is also a fintype.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_left_inverse {g : B → A} {f : A →ₐ[R] B} (h : function.left_inverse g f) : A ≃ₐ[R] f.range
{ to_fun := f.range_restrict, inv_fun := g ∘ f.range.val, left_inv := h, right_inv := λ x, subtype.ext $ let ⟨x', hx'⟩ := f.mem_range.mp x.prop in show f (g x) = x, by rw [←hx', h x'], ..f.range_restrict }
def
alg_equiv.of_left_inverse
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "inv_fun", "subtype.ext" ]
Restrict an algebra homomorphism with a left inverse to an algebra isomorphism to its range. This is a computable alternative to `alg_equiv.of_injective`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_left_inverse_apply {g : B → A} {f : A →ₐ[R] B} (h : function.left_inverse g f) (x : A) : ↑(of_left_inverse h x) = f x
rfl
lemma
alg_equiv.of_left_inverse_apply
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_left_inverse_symm_apply {g : B → A} {f : A →ₐ[R] B} (h : function.left_inverse g f) (x : f.range) : (of_left_inverse h).symm x = g x
rfl
lemma
alg_equiv.of_left_inverse_symm_apply
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_injective (f : A →ₐ[R] B) (hf : function.injective f) : A ≃ₐ[R] f.range
of_left_inverse (classical.some_spec hf.has_left_inverse)
def
alg_equiv.of_injective
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[]
Restrict an injective algebra homomorphism to an algebra isomorphism
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_injective_apply (f : A →ₐ[R] B) (hf : function.injective f) (x : A) : ↑(of_injective f hf x) = f x
rfl
lemma
alg_equiv.of_injective_apply
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_injective_field {E F : Type*} [division_ring E] [semiring F] [nontrivial F] [algebra R E] [algebra R F] (f : E →ₐ[R] F) : E ≃ₐ[R] f.range
of_injective f f.to_ring_hom.injective
def
alg_equiv.of_injective_field
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra", "division_ring", "nontrivial", "semiring" ]
Restrict an algebra homomorphism between fields to an algebra isomorphism
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subalgebra_map (e : A ≃ₐ[R] B) (S : subalgebra R A) : S ≃ₐ[R] (S.map e.to_alg_hom)
{ commutes' := λ r, by { ext, simp }, ..e.to_ring_equiv.subsemiring_map S.to_subsemiring }
def
alg_equiv.subalgebra_map
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
Given an equivalence `e : A ≃ₐ[R] B` of `R`-algebras and a subalgebra `S` of `A`, `subalgebra_map` is the induced equivalence between `S` and `S.map e`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
adjoin (s : set A) : subalgebra R A
{ algebra_map_mem' := λ r, subsemiring.subset_closure $ or.inl ⟨r, rfl⟩, .. subsemiring.closure (set.range (algebra_map R A) ∪ s) }
def
algebra.adjoin
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra_map", "set.range", "subalgebra", "subsemiring.closure", "subsemiring.subset_closure" ]
The minimal subalgebra that includes `s`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gc : galois_connection (adjoin R : set A → subalgebra R A) coe
λ s S, ⟨λ H, le_trans (le_trans (set.subset_union_right _ _) subsemiring.subset_closure) H, λ H, show subsemiring.closure (set.range (algebra_map R A) ∪ s) ≤ S.to_subsemiring, from subsemiring.closure_le.2 $ set.union_subset S.range_subset H⟩
lemma
algebra.gc
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra_map", "galois_connection", "set.range", "set.subset_union_right", "set.union_subset", "subalgebra", "subsemiring.closure", "subsemiring.subset_closure" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gi : galois_insertion (adjoin R : set A → subalgebra R A) coe
{ choice := λ s hs, (adjoin R s).copy s $ le_antisymm (algebra.gc.le_u_l s) hs, gc := algebra.gc, le_l_u := λ S, (algebra.gc (S : set A) (adjoin R S)).1 $ le_rfl, choice_eq := λ _ _, subalgebra.copy_eq _ _ _ }
def
algebra.gi
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra.gc", "galois_insertion", "le_rfl", "subalgebra", "subalgebra.copy_eq" ]
Galois insertion between `adjoin` and `coe`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_top : (↑(⊤ : subalgebra R A) : set A) = set.univ
rfl
lemma
algebra.coe_top
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_top {x : A} : x ∈ (⊤ : subalgebra R A)
set.mem_univ x
lemma
algebra.mem_top
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.mem_univ", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
top_to_submodule : (⊤ : subalgebra R A).to_submodule = ⊤
rfl
lemma
algebra.top_to_submodule
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
top_to_subsemiring : (⊤ : subalgebra R A).to_subsemiring = ⊤
rfl
lemma
algebra.top_to_subsemiring
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
top_to_subring {R A : Type*} [comm_ring R] [ring A] [algebra R A] : (⊤ : subalgebra R A).to_subring = ⊤
rfl
lemma
algebra.top_to_subring
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra", "comm_ring", "ring", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_submodule_eq_top {S : subalgebra R A} : S.to_submodule = ⊤ ↔ S = ⊤
subalgebra.to_submodule.injective.eq_iff' top_to_submodule
lemma
algebra.to_submodule_eq_top
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_subsemiring_eq_top {S : subalgebra R A} : S.to_subsemiring = ⊤ ↔ S = ⊤
subalgebra.to_subsemiring_injective.eq_iff' top_to_subsemiring
lemma
algebra.to_subsemiring_eq_top
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_subring_eq_top {R A : Type*} [comm_ring R] [ring A] [algebra R A] {S : subalgebra R A} : S.to_subring = ⊤ ↔ S = ⊤
subalgebra.to_subring_injective.eq_iff' top_to_subring
lemma
algebra.to_subring_eq_top
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra", "comm_ring", "ring", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_sup_left {S T : subalgebra R A} : ∀ {x : A}, x ∈ S → x ∈ S ⊔ T
show S ≤ S ⊔ T, from le_sup_left
lemma
algebra.mem_sup_left
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "le_sup_left", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_sup_right {S T : subalgebra R A} : ∀ {x : A}, x ∈ T → x ∈ S ⊔ T
show T ≤ S ⊔ T, from le_sup_right
lemma
algebra.mem_sup_right
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "le_sup_right", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_mem_sup {S T : subalgebra R A} {x y : A} (hx : x ∈ S) (hy : y ∈ T) : x * y ∈ S ⊔ T
(S ⊔ T).mul_mem (mem_sup_left hx) (mem_sup_right hy)
lemma
algebra.mul_mem_sup
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_sup (f : A →ₐ[R] B) (S T : subalgebra R A) : (S ⊔ T).map f = S.map f ⊔ T.map f
(subalgebra.gc_map_comap f).l_sup
lemma
algebra.map_sup
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra", "subalgebra.gc_map_comap" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_inf (S T : subalgebra R A) : (↑(S ⊓ T) : set A) = S ∩ T
rfl
lemma
algebra.coe_inf
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_inf {S T : subalgebra R A} {x : A} : x ∈ S ⊓ T ↔ x ∈ S ∧ x ∈ T
iff.rfl
lemma
algebra.mem_inf
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inf_to_submodule (S T : subalgebra R A) : (S ⊓ T).to_submodule = S.to_submodule ⊓ T.to_submodule
rfl
lemma
algebra.inf_to_submodule
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inf_to_subsemiring (S T : subalgebra R A) : (S ⊓ T).to_subsemiring = S.to_subsemiring ⊓ T.to_subsemiring
rfl
lemma
algebra.inf_to_subsemiring
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_Inf (S : set (subalgebra R A)) : (↑(Inf S) : set A) = ⋂ s ∈ S, ↑s
Inf_image
lemma
algebra.coe_Inf
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "Inf_image", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_Inf {S : set (subalgebra R A)} {x : A} : x ∈ Inf S ↔ ∀ p ∈ S, x ∈ p
by simp only [← set_like.mem_coe, coe_Inf, set.mem_Inter₂]
lemma
algebra.mem_Inf
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.mem_Inter₂", "set_like.mem_coe", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Inf_to_submodule (S : set (subalgebra R A)) : (Inf S).to_submodule = Inf (subalgebra.to_submodule '' S)
set_like.coe_injective $ by simp
lemma
algebra.Inf_to_submodule
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set_like.coe_injective", "subalgebra", "subalgebra.to_submodule" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Inf_to_subsemiring (S : set (subalgebra R A)) : (Inf S).to_subsemiring = Inf (subalgebra.to_subsemiring '' S)
set_like.coe_injective $ by simp
lemma
algebra.Inf_to_subsemiring
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set_like.coe_injective", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_infi {ι : Sort*} {S : ι → subalgebra R A} : (↑(⨅ i, S i) : set A) = ⋂ i, S i
by simp [infi]
lemma
algebra.coe_infi
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "infi", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_infi {ι : Sort*} {S : ι → subalgebra R A} {x : A} : (x ∈ ⨅ i, S i) ↔ ∀ i, x ∈ S i
by simp only [infi, mem_Inf, set.forall_range_iff]
lemma
algebra.mem_infi
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "infi", "set.forall_range_iff", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
infi_to_submodule {ι : Sort*} (S : ι → subalgebra R A) : (⨅ i, S i).to_submodule = ⨅ i, (S i).to_submodule
set_like.coe_injective $ by simp
lemma
algebra.infi_to_submodule
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set_like.coe_injective", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_bot {x : A} : x ∈ (⊥ : subalgebra R A) ↔ x ∈ set.range (algebra_map R A)
suffices (of_id R A).range = (⊥ : subalgebra R A), by { rw [← this, ←set_like.mem_coe, alg_hom.coe_range], refl }, le_bot_iff.mp (λ x hx, subalgebra.range_le _ ((of_id R A).coe_range ▸ hx))
theorem
algebra.mem_bot
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_hom.coe_range", "algebra_map", "set.range", "subalgebra", "subalgebra.range_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_submodule_bot : (⊥ : subalgebra R A).to_submodule = R ∙ 1
by { ext x, simp [mem_bot, -set.singleton_one, submodule.mem_span_singleton, algebra.smul_def] }
theorem
algebra.to_submodule_bot
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra.smul_def", "set.singleton_one", "subalgebra", "submodule.mem_span_singleton" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_bot : ((⊥ : subalgebra R A) : set A) = set.range (algebra_map R A)
by simp [set.ext_iff, algebra.mem_bot]
theorem
algebra.coe_bot
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra.mem_bot", "algebra_map", "set.ext_iff", "set.range", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_top_iff {S : subalgebra R A} : S = ⊤ ↔ ∀ x : A, x ∈ S
⟨λ h x, by rw h; exact mem_top, λ h, by ext x; exact ⟨λ _, mem_top, λ _, h x⟩⟩
theorem
algebra.eq_top_iff
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "eq_top_iff", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_top_iff_surjective (f : A →ₐ[R] B) : f.range = (⊤ : subalgebra R B) ↔ function.surjective f
algebra.eq_top_iff
lemma
algebra.range_top_iff_surjective
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra.eq_top_iff", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_id : (alg_hom.id R A).range = ⊤
set_like.coe_injective set.range_id
theorem
algebra.range_id
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_hom.id", "set.range_id", "set_like.coe_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_top (f : A →ₐ[R] B) : (⊤ : subalgebra R A).map f = f.range
set_like.coe_injective set.image_univ
theorem
algebra.map_top
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.image_univ", "set_like.coe_injective", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_bot (f : A →ₐ[R] B) : (⊥ : subalgebra R A).map f = ⊥
set_like.coe_injective $ by simp only [← set.range_comp, (∘), algebra.coe_bot, subalgebra.coe_map, f.commutes]
theorem
algebra.map_bot
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra.coe_bot", "set.range_comp", "set_like.coe_injective", "subalgebra", "subalgebra.coe_map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_top (f : A →ₐ[R] B) : (⊤ : subalgebra R B).comap f = ⊤
eq_top_iff.2 $ λ x, mem_top
theorem
algebra.comap_top
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_top : A →ₐ[R] (⊤ : subalgebra R A)
(alg_hom.id R A).cod_restrict ⊤ (λ _, mem_top)
def
algebra.to_top
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_hom.id", "subalgebra", "to_top" ]
`alg_hom` to `⊤ : subalgebra R A`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
surjective_algebra_map_iff : function.surjective (algebra_map R A) ↔ (⊤ : subalgebra R A) = ⊥
⟨λ h, eq_bot_iff.2 $ λ y _, let ⟨x, hx⟩ := h y in hx ▸ subalgebra.algebra_map_mem _ _, λ h y, algebra.mem_bot.1 $ eq_bot_iff.1 h (algebra.mem_top : y ∈ _)⟩
theorem
algebra.surjective_algebra_map_iff
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra.mem_top", "algebra_map", "subalgebra", "subalgebra.algebra_map_mem" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bijective_algebra_map_iff {R A : Type*} [field R] [semiring A] [nontrivial A] [algebra R A] : function.bijective (algebra_map R A) ↔ (⊤ : subalgebra R A) = ⊥
⟨λ h, surjective_algebra_map_iff.1 h.2, λ h, ⟨(algebra_map R A).injective, surjective_algebra_map_iff.2 h⟩⟩
theorem
algebra.bijective_algebra_map_iff
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra", "algebra_map", "field", "nontrivial", "semiring", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bot_equiv_of_injective (h : function.injective (algebra_map R A)) : (⊥ : subalgebra R A) ≃ₐ[R] R
alg_equiv.symm $ alg_equiv.of_bijective (algebra.of_id R _) ⟨λ x y hxy, h (congr_arg subtype.val hxy : _), λ ⟨y, hy⟩, let ⟨x, hx⟩ := algebra.mem_bot.1 hy in ⟨x, subtype.eq hx⟩⟩
def
algebra.bot_equiv_of_injective
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_equiv.of_bijective", "alg_equiv.symm", "algebra.of_id", "algebra_map", "subalgebra" ]
The bottom subalgebra is isomorphic to the base ring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bot_equiv (F R : Type*) [field F] [semiring R] [nontrivial R] [algebra F R] : (⊥ : subalgebra F R) ≃ₐ[F] F
bot_equiv_of_injective (ring_hom.injective _)
def
algebra.bot_equiv
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra", "field", "nontrivial", "ring_hom.injective", "semiring", "subalgebra" ]
The bottom subalgebra is isomorphic to the field.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
top_equiv : (⊤ : subalgebra R A) ≃ₐ[R] A
alg_equiv.of_alg_hom (subalgebra.val ⊤) to_top rfl $ alg_hom.ext $ λ _, subtype.ext rfl
def
subalgebra.top_equiv
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_equiv.of_alg_hom", "alg_hom.ext", "subalgebra", "subalgebra.val", "subtype.ext", "to_top" ]
The top subalgebra is isomorphic to the algebra. This is the algebra version of `submodule.top_equiv`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subsingleton_of_subsingleton [subsingleton A] : subsingleton (subalgebra R A)
⟨λ B C, ext (λ x, by { simp only [subsingleton.elim x 0, zero_mem B, zero_mem C] })⟩
instance
subalgebra.subsingleton_of_subsingleton
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.alg_hom.subsingleton [subsingleton (subalgebra R A)] : subsingleton (A →ₐ[R] B)
⟨λ f g, alg_hom.ext $ λ a, have a ∈ (⊥ : subalgebra R A) := subsingleton.elim (⊤ : subalgebra R A) ⊥ ▸ mem_top, let ⟨x, hx⟩ := set.mem_range.mp (mem_bot.mp this) in hx ▸ (f.commutes _).trans (g.commutes _).symm⟩
instance
alg_hom.subsingleton
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_hom.ext", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.alg_equiv.subsingleton_left [subsingleton (subalgebra R A)] : subsingleton (A ≃ₐ[R] B)
⟨λ f g, alg_equiv.ext (λ x, alg_hom.ext_iff.mp (subsingleton.elim f.to_alg_hom g.to_alg_hom) x)⟩
instance
alg_equiv.subsingleton_left
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_equiv.ext", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.alg_equiv.subsingleton_right [subsingleton (subalgebra R B)] : subsingleton (A ≃ₐ[R] B)
⟨λ f g, by rw [← f.symm_symm, subsingleton.elim f.symm g.symm, g.symm_symm]⟩
instance
alg_equiv.subsingleton_right
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_val : S.val.range = S
ext $ set.ext_iff.1 $ S.val.coe_range.trans subtype.range_val
lemma
subalgebra.range_val
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subtype.range_val" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inclusion {S T : subalgebra R A} (h : S ≤ T) : S →ₐ[R] T
{ to_fun := set.inclusion h, map_one' := rfl, map_add' := λ _ _, rfl, map_mul' := λ _ _, rfl, map_zero' := rfl, commutes' := λ _, rfl }
def
subalgebra.inclusion
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.inclusion", "subalgebra" ]
The map `S → T` when `S` is a subalgebra contained in the subalgebra `T`. This is the subalgebra version of `submodule.of_le`, or `subring.inclusion`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inclusion_injective {S T : subalgebra R A} (h : S ≤ T) : function.injective (inclusion h)
λ _ _, subtype.ext ∘ subtype.mk.inj
lemma
subalgebra.inclusion_injective
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra", "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inclusion_self {S : subalgebra R A}: inclusion (le_refl S) = alg_hom.id R S
alg_hom.ext $ λ x, subtype.ext rfl
lemma
subalgebra.inclusion_self
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_hom.ext", "alg_hom.id", "subalgebra", "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inclusion_mk {S T : subalgebra R A} (h : S ≤ T) (x : A) (hx : x ∈ S) : inclusion h ⟨x, hx⟩ = ⟨x, h hx⟩
rfl
lemma
subalgebra.inclusion_mk
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inclusion_right {S T : subalgebra R A} (h : S ≤ T) (x : T) (m : (x : A) ∈ S) : inclusion h ⟨x, m⟩ = x
subtype.ext rfl
lemma
subalgebra.inclusion_right
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra", "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inclusion_inclusion {S T U : subalgebra R A} (hst : S ≤ T) (htu : T ≤ U) (x : S) : inclusion htu (inclusion hst x) = inclusion (le_trans hst htu) x
subtype.ext rfl
lemma
subalgebra.inclusion_inclusion
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra", "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_inclusion {S T : subalgebra R A} (h : S ≤ T) (s : S) : (inclusion h s : A) = s
rfl
lemma
subalgebra.coe_inclusion
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv_of_eq (S T : subalgebra R A) (h : S = T) : S ≃ₐ[R] T
{ to_fun := λ x, ⟨x, h ▸ x.2⟩, inv_fun := λ x, ⟨x, h.symm ▸ x.2⟩, map_mul' := λ _ _, rfl, commutes' := λ _, rfl, .. linear_equiv.of_eq _ _ (congr_arg to_submodule h) }
def
subalgebra.equiv_of_eq
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "inv_fun", "linear_equiv.of_eq", "subalgebra" ]
Two subalgebras that are equal are also equivalent as algebras. This is the `subalgebra` version of `linear_equiv.of_eq` and `equiv.set.of_eq`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv_of_eq_symm (S T : subalgebra R A) (h : S = T) : (equiv_of_eq S T h).symm = equiv_of_eq T S h.symm
rfl
lemma
subalgebra.equiv_of_eq_symm
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv_of_eq_rfl (S : subalgebra R A) : equiv_of_eq S S rfl = alg_equiv.refl
by { ext, refl }
lemma
subalgebra.equiv_of_eq_rfl
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_equiv.refl", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv_of_eq_trans (S T U : subalgebra R A) (hST : S = T) (hTU : T = U) : (equiv_of_eq S T hST).trans (equiv_of_eq T U hTU) = equiv_of_eq S U (trans hST hTU)
rfl
lemma
subalgebra.equiv_of_eq_trans
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod : subalgebra R (A × B)
{ carrier := S ×ˢ S₁, algebra_map_mem' := λ r, ⟨algebra_map_mem _ _, algebra_map_mem _ _⟩, .. S.to_subsemiring.prod S₁.to_subsemiring }
def
subalgebra.prod
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
The product of two subalgebras is a subalgebra.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_prod : (prod S S₁ : set (A × B)) = S ×ˢ S₁
rfl
lemma
subalgebra.coe_prod
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_to_submodule : (S.prod S₁).to_submodule = S.to_submodule.prod S₁.to_submodule
rfl
lemma
subalgebra.prod_to_submodule
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_prod {S : subalgebra R A} {S₁ : subalgebra R B} {x : A × B} : x ∈ prod S S₁ ↔ x.1 ∈ S ∧ x.2 ∈ S₁
set.mem_prod
lemma
subalgebra.mem_prod
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.mem_prod", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_top : (prod ⊤ ⊤ : subalgebra R (A × B)) = ⊤
by ext; simp
lemma
subalgebra.prod_top
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_mono {S T : subalgebra R A} {S₁ T₁ : subalgebra R B} : S ≤ T → S₁ ≤ T₁ → prod S S₁ ≤ prod T T₁
set.prod_mono
lemma
subalgebra.prod_mono
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.prod_mono", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_inf_prod {S T : subalgebra R A} {S₁ T₁ : subalgebra R B} : S.prod S₁ ⊓ T.prod T₁ = (S ⊓ T).prod (S₁ ⊓ T₁)
set_like.coe_injective set.prod_inter_prod
lemma
subalgebra.prod_inf_prod
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.prod_inter_prod", "set_like.coe_injective", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_supr_of_directed [nonempty ι] {S : ι → subalgebra R A} (dir : directed (≤) S) : ↑(supr S) = ⋃ i, (S i : set A)
let K : subalgebra R A := { carrier := ⋃ i, (S i), mul_mem' := λ x y hx hy, let ⟨i, hi⟩ := set.mem_Union.1 hx in let ⟨j, hj⟩ := set.mem_Union.1 hy in let ⟨k, hik, hjk⟩ := dir i j in set.mem_Union.2 ⟨k, subalgebra.mul_mem (S k) (hik hi) (hjk hj)⟩ , add_mem' := λ x y hx hy, let ⟨i,...
lemma
subalgebra.coe_supr_of_directed
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "directed", "le_supr", "nonempty.some", "set.Union_subset", "set.subset_Union", "subalgebra", "subalgebra.add_mem", "subalgebra.algebra_map_mem", "subalgebra.mul_mem", "supr", "supr_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
supr_lift [nonempty ι] (K : ι → subalgebra R A) (dir : directed (≤) K) (f : Π i, K i →ₐ[R] B) (hf : ∀ (i j : ι) (h : K i ≤ K j), f i = (f j).comp (inclusion h)) (T : subalgebra R A) (hT : T = supr K) : ↥T →ₐ[R] B
by subst hT; exact { to_fun := set.Union_lift (λ i, ↑(K i)) (λ i x, f i x) (λ i j x hxi hxj, let ⟨k, hik, hjk⟩ := dir i j in begin rw [hf i k hik, hf j k hjk], refl end) ↑(supr K) (by rw coe_supr_of_directed dir; refl), map_one' := set.Union_lift_const _ (λ _, 1) (λ _, rfl) _...
def
subalgebra.supr_lift
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "alg_hom.commutes", "algebra_map", "directed", "set.Union_lift", "set.Union_lift_binary", "set.Union_lift_const", "subalgebra", "supr" ]
Define an algebra homomorphism on a directed supremum of subalgebras by defining it on each subalgebra, and proving that it agrees on the intersection of subalgebras.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
supr_lift_inclusion {i : ι} (x : K i) (h : K i ≤ T) : supr_lift K dir f hf T hT (inclusion h x) = f i x
by subst T; exact set.Union_lift_inclusion _ _
lemma
subalgebra.supr_lift_inclusion
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.Union_lift_inclusion" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
supr_lift_comp_inclusion {i : ι} (h : K i ≤ T) : (supr_lift K dir f hf T hT).comp (inclusion h) = f i
by ext; simp
lemma
subalgebra.supr_lift_comp_inclusion
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
supr_lift_mk {i : ι} (x : K i) (hx : (x : A) ∈ T) : supr_lift K dir f hf T hT ⟨x, hx⟩ = f i x
by subst hT; exact set.Union_lift_mk x hx
lemma
subalgebra.supr_lift_mk
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.Union_lift_mk" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
supr_lift_of_mem {i : ι} (x : T) (hx : (x : A) ∈ K i) : supr_lift K dir f hf T hT x = f i ⟨x, hx⟩
by subst hT; exact set.Union_lift_of_mem x hx
lemma
subalgebra.supr_lift_of_mem
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "set.Union_lift_of_mem" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_def [has_smul A α] {S : subalgebra R A} (g : S) (m : α) : g • m = (g : A) • m
rfl
lemma
subalgebra.smul_def
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "has_smul", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_comm_class_left [has_smul A β] [has_smul α β] [smul_comm_class A α β] (S : subalgebra R A) : smul_comm_class S α β
S.to_subsemiring.smul_comm_class_left
instance
subalgebra.smul_comm_class_left
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "has_smul", "smul_comm_class", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_comm_class_right [has_smul α β] [has_smul A β] [smul_comm_class α A β] (S : subalgebra R A) : smul_comm_class α S β
S.to_subsemiring.smul_comm_class_right
instance
subalgebra.smul_comm_class_right
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "has_smul", "smul_comm_class", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_scalar_tower_left [has_smul α β] [has_smul A α] [has_smul A β] [is_scalar_tower A α β] (S : subalgebra R A) : is_scalar_tower S α β
S.to_subsemiring.is_scalar_tower
instance
subalgebra.is_scalar_tower_left
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "has_smul", "is_scalar_tower", "subalgebra" ]
Note that this provides `is_scalar_tower S R R` which is needed by `smul_mul_assoc`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_scalar_tower_mid {R S T : Type*} [comm_semiring R] [semiring S] [add_comm_monoid T] [algebra R S] [module R T] [module S T] [is_scalar_tower R S T] (S' : subalgebra R S) : is_scalar_tower R S' T
⟨λ x y z, (smul_assoc _ (y : S) _ : _)⟩
instance
subalgebra.is_scalar_tower_mid
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "add_comm_monoid", "algebra", "comm_semiring", "is_scalar_tower", "module", "semiring", "smul_assoc", "subalgebra" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
module_left [add_comm_monoid α] [module A α] (S : subalgebra R A) : module S α
S.to_subsemiring.module
instance
subalgebra.module_left
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "add_comm_monoid", "module", "subalgebra" ]
The action by a subalgebra is the action by the underlying algebra.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_algebra {R A : Type*} [comm_semiring R] [comm_semiring A] [semiring α] [algebra R A] [algebra A α] (S : subalgebra R A) : algebra S α
algebra.of_subsemiring S.to_subsemiring
instance
subalgebra.to_algebra
algebra.algebra.subalgebra
src/algebra/algebra/subalgebra/basic.lean
[ "algebra.algebra.basic", "data.set.Union_lift", "linear_algebra.finsupp", "ring_theory.ideal.operations" ]
[ "algebra", "algebra.of_subsemiring", "comm_semiring", "semiring", "subalgebra" ]
The action by a subalgebra is the action by the underlying algebra.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83