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zero_eq [nontrivial A] : σ (0 : A) = {0}
begin refine set.subset.antisymm _ (by simp [algebra.algebra_map_eq_smul_one, mem_iff]), rw [spectrum, set.compl_subset_comm], intros k hk, rw set.mem_compl_singleton_iff at hk, have : is_unit (units.mk0 k hk • (1 : A)) := is_unit.smul (units.mk0 k hk) is_unit_one, simpa [mem_resolvent_set_iff, algebra.alge...
lemma
spectrum.zero_eq
algebra.algebra
src/algebra/algebra/spectrum.lean
[ "algebra.star.pointwise", "algebra.star.subalgebra", "tactic.noncomm_ring" ]
[ "algebra.algebra_map_eq_smul_one", "is_unit", "is_unit.smul", "is_unit_one", "nontrivial", "set.compl_subset_comm", "set.mem_compl_singleton_iff", "set.subset.antisymm", "spectrum", "units.mk0" ]
Without the assumption `nontrivial A`, then `0 : A` would be invertible.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
scalar_eq [nontrivial A] (k : 𝕜) : σ (↑ₐk) = {k}
by rw [←add_zero (↑ₐk), ←singleton_add_eq, zero_eq, set.singleton_add_singleton, add_zero]
theorem
spectrum.scalar_eq
algebra.algebra
src/algebra/algebra/spectrum.lean
[ "algebra.star.pointwise", "algebra.star.subalgebra", "tactic.noncomm_ring" ]
[ "nontrivial" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_eq [nontrivial A] : σ (1 : A) = {1}
calc σ (1 : A) = σ (↑ₐ1) : by rw [algebra.algebra_map_eq_smul_one, one_smul] ... = {1} : scalar_eq 1
lemma
spectrum.one_eq
algebra.algebra
src/algebra/algebra/spectrum.lean
[ "algebra.star.pointwise", "algebra.star.subalgebra", "tactic.noncomm_ring" ]
[ "algebra.algebra_map_eq_smul_one", "nontrivial", "one_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_eq_smul [nontrivial A] (k : 𝕜) (a : A) (ha : (σ a).nonempty) : σ (k • a) = k • (σ a)
begin rcases eq_or_ne k 0 with rfl | h, { simpa [ha, zero_smul_set] }, { exact unit_smul_eq_smul a (units.mk0 k h) }, end
theorem
spectrum.smul_eq_smul
algebra.algebra
src/algebra/algebra/spectrum.lean
[ "algebra.star.pointwise", "algebra.star.subalgebra", "tactic.noncomm_ring" ]
[ "eq_or_ne", "nontrivial", "units.mk0" ]
the assumption `(σ a).nonempty` is necessary and cannot be removed without further conditions on the algebra `A` and scalar field `𝕜`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonzero_mul_eq_swap_mul (a b : A) : σ (a * b) \ {0} = σ (b * a) \ {0}
begin suffices h : ∀ (x y : A), σ (x * y) \ {0} ⊆ σ (y * x) \ {0}, { exact set.eq_of_subset_of_subset (h a b) (h b a) }, { rintros _ _ k ⟨k_mem, k_neq⟩, change k with ↑(units.mk0 k k_neq) at k_mem, exact ⟨unit_mem_mul_iff_mem_swap_mul.mp k_mem, k_neq⟩ }, end
theorem
spectrum.nonzero_mul_eq_swap_mul
algebra.algebra
src/algebra/algebra/spectrum.lean
[ "algebra.star.pointwise", "algebra.star.subalgebra", "tactic.noncomm_ring" ]
[ "set.eq_of_subset_of_subset", "units.mk0" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_inv (a : Aˣ) : (σ (a : A))⁻¹ = σ (↑a⁻¹ : A)
begin refine set.eq_of_subset_of_subset (λ k hk, _) (λ k hk, _), { rw set.mem_inv at hk, have : k ≠ 0, { simpa only [inv_inv] using inv_ne_zero (ne_zero_of_mem_of_unit hk), }, lift k to 𝕜ˣ using is_unit_iff_ne_zero.mpr this, rw ←units.coe_inv k at hk, exact inv_mem_iff.mp hk }, { lift k to 𝕜...
lemma
spectrum.map_inv
algebra.algebra
src/algebra/algebra/spectrum.lean
[ "algebra.star.pointwise", "algebra.star.subalgebra", "tactic.noncomm_ring" ]
[ "inv_inv", "inv_ne_zero", "lift", "map_inv", "set.eq_of_subset_of_subset", "set.mem_inv", "units.coe_inv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_resolvent_set_apply (φ : F) {a : A} {r : R} (h : r ∈ resolvent_set R a) : r ∈ resolvent_set R ((φ : A → B) a)
by simpa only [map_sub, alg_hom_class.commutes] using h.map φ
lemma
alg_hom.mem_resolvent_set_apply
algebra.algebra
src/algebra/algebra/spectrum.lean
[ "algebra.star.pointwise", "algebra.star.subalgebra", "tactic.noncomm_ring" ]
[ "resolvent_set" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
spectrum_apply_subset (φ : F) (a : A) : σ ((φ : A → B) a) ⊆ σ a
λ _, mt (mem_resolvent_set_apply φ)
lemma
alg_hom.spectrum_apply_subset
algebra.algebra
src/algebra/algebra/spectrum.lean
[ "algebra.star.pointwise", "algebra.star.subalgebra", "tactic.noncomm_ring" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
apply_mem_spectrum [nontrivial R] (φ : F) (a : A) : φ a ∈ σ a
begin have h : ↑ₐ(φ a) - a ∈ (φ : A →+* R).ker, { simp only [ring_hom.mem_ker, map_sub, ring_hom.coe_coe, alg_hom_class.commutes, algebra.id.map_eq_id, ring_hom.id_apply, sub_self], }, simp only [spectrum.mem_iff, ←mem_nonunits_iff, coe_subset_nonunits ((φ : A →+* R).ker_ne_top) h], end
lemma
alg_hom.apply_mem_spectrum
algebra.algebra
src/algebra/algebra/spectrum.lean
[ "algebra.star.pointwise", "algebra.star.subalgebra", "tactic.noncomm_ring" ]
[ "algebra.id.map_eq_id", "coe_subset_nonunits", "nontrivial", "ring_hom.coe_coe", "ring_hom.id_apply", "ring_hom.mem_ker", "spectrum.mem_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lsmul : A →ₐ[R] module.End R M
{ to_fun := distrib_mul_action.to_linear_map R M, map_one' := linear_map.ext $ λ _, one_smul A _, map_mul' := λ a b, linear_map.ext $ smul_assoc a b, map_zero' := linear_map.ext $ λ _, zero_smul A _, map_add' := λ a b, linear_map.ext $ λ _, add_smul _ _ _, commutes' := λ r, linear_map.ext $ algebra_map_smul A...
def
algebra.lsmul
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "add_smul", "algebra_map_smul", "distrib_mul_action.to_linear_map", "linear_map.ext", "module.End", "one_smul", "smul_assoc", "zero_smul" ]
The `R`-algebra morphism `A → End (M)` corresponding to the representation of the algebra `A` on the `R`-module `M`. This is a stronger version of `distrib_mul_action.to_linear_map`, and could also have been called `algebra.to_module_End`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lsmul_coe (a : A) : (lsmul R M a : M → M) = (•) a
rfl
lemma
algebra.lsmul_coe
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
algebra_map_smul (r : R) (x : M) : algebra_map R A r • x = r • x
by rw [algebra.algebra_map_eq_smul_one, smul_assoc, one_smul]
theorem
is_scalar_tower.algebra_map_smul
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra.algebra_map_eq_smul_one", "algebra_map", "algebra_map_smul", "one_smul", "smul_assoc" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_algebra_map_eq [algebra R A] (h : ∀ x, algebra_map R A x = algebra_map S A (algebra_map R S x)) : is_scalar_tower R S A
⟨λ x y z, by simp_rw [algebra.smul_def, ring_hom.map_mul, mul_assoc, h]⟩
theorem
is_scalar_tower.of_algebra_map_eq
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra", "algebra.smul_def", "algebra_map", "is_scalar_tower", "mul_assoc", "ring_hom.map_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_algebra_map_eq' [algebra R A] (h : algebra_map R A = (algebra_map S A).comp (algebra_map R S)) : is_scalar_tower R S A
of_algebra_map_eq $ ring_hom.ext_iff.1 h
theorem
is_scalar_tower.of_algebra_map_eq'
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra", "algebra_map", "is_scalar_tower" ]
See note [partially-applied ext lemmas].
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
algebra_map_eq : algebra_map R A = (algebra_map S A).comp (algebra_map R S)
ring_hom.ext $ λ x, by simp_rw [ring_hom.comp_apply, algebra.algebra_map_eq_smul_one, smul_assoc, one_smul]
theorem
is_scalar_tower.algebra_map_eq
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra.algebra_map_eq_smul_one", "algebra_map", "one_smul", "ring_hom.comp_apply", "ring_hom.ext", "smul_assoc" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
algebra_map_apply (x : R) : algebra_map R A x = algebra_map S A (algebra_map R S x)
by rw [algebra_map_eq R S A, ring_hom.comp_apply]
theorem
is_scalar_tower.algebra_map_apply
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra_map", "algebra_map_apply", "ring_hom.comp_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
algebra.ext {S : Type u} {A : Type v} [comm_semiring S] [semiring A] (h1 h2 : algebra S A) (h : ∀ (r : S) (x : A), (by haveI := h1; exact r • x) = r • x) : h1 = h2
algebra.algebra_ext _ _ $ λ r, by simpa only [@algebra.smul_def _ _ _ _ h1, @algebra.smul_def _ _ _ _ h2, mul_one] using h r 1
lemma
is_scalar_tower.algebra.ext
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra", "algebra.algebra_ext", "algebra.smul_def", "comm_semiring", "mul_one", "semiring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_alg_hom : S →ₐ[R] A
{ commutes' := λ _, (algebra_map_apply _ _ _ _).symm, .. algebra_map S A }
def
is_scalar_tower.to_alg_hom
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra_map", "algebra_map_apply" ]
In a tower, the canonical map from the middle element to the top element is an algebra homomorphism over the bottom element.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_alg_hom_apply (y : S) : to_alg_hom R S A y = algebra_map S A y
rfl
lemma
is_scalar_tower.to_alg_hom_apply
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra_map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_to_alg_hom : ↑(to_alg_hom R S A) = algebra_map S A
ring_hom.ext $ λ _, rfl
lemma
is_scalar_tower.coe_to_alg_hom
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra_map", "ring_hom.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_to_alg_hom' : (to_alg_hom R S A : S → A) = algebra_map S A
rfl
lemma
is_scalar_tower.coe_to_alg_hom'
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra_map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.alg_hom.map_algebra_map (f : A →ₐ[S] B) (r : R) : f (algebra_map R A r) = algebra_map R B r
by rw [algebra_map_apply R S A r, f.commutes, ← algebra_map_apply R S B]
lemma
alg_hom.map_algebra_map
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra_map", "algebra_map_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.alg_hom.comp_algebra_map_of_tower (f : A →ₐ[S] B) : (f : A →+* B).comp (algebra_map R A) = algebra_map R B
ring_hom.ext f.map_algebra_map
lemma
alg_hom.comp_algebra_map_of_tower
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra_map", "ring_hom.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subsemiring (U : subsemiring S) : is_scalar_tower U S A
of_algebra_map_eq $ λ x, rfl
instance
is_scalar_tower.subsemiring
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "is_scalar_tower", "subsemiring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_ring_hom {R A B : Type*} [comm_semiring R] [comm_semiring A] [comm_semiring B] [algebra R A] [algebra R B] (f : A →ₐ[R] B) : @is_scalar_tower R A B _ (f.to_ring_hom.to_algebra.to_has_smul) _
by { letI := (f : A →+* B).to_algebra, exact of_algebra_map_eq (λ x, (f.commutes x).symm) }
instance
is_scalar_tower.of_ring_hom
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra", "comm_semiring", "is_scalar_tower" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_scalars (f : A →ₐ[S] B) : A →ₐ[R] B
{ commutes' := λ r, by { rw [algebra_map_apply R S A, algebra_map_apply R S B], exact f.commutes (algebra_map R S r) }, .. (f : A →+* B) }
def
alg_hom.restrict_scalars
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra_map", "algebra_map_apply", "restrict_scalars" ]
R ⟶ S induces S-Alg ⥤ R-Alg
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_scalars_apply (f : A →ₐ[S] B) (x : A) : f.restrict_scalars R x = f x
rfl
lemma
alg_hom.restrict_scalars_apply
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_restrict_scalars (f : A →ₐ[S] B) : (f.restrict_scalars R : A →+* B) = f
rfl
lemma
alg_hom.coe_restrict_scalars
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_restrict_scalars' (f : A →ₐ[S] B) : (restrict_scalars R f : A → B) = f
rfl
lemma
alg_hom.coe_restrict_scalars'
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "restrict_scalars" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_scalars_injective : function.injective (restrict_scalars R : (A →ₐ[S] B) → (A →ₐ[R] B))
λ f g h, alg_hom.ext (alg_hom.congr_fun h : _)
lemma
alg_hom.restrict_scalars_injective
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "alg_hom.congr_fun", "alg_hom.ext", "restrict_scalars" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_scalars (f : A ≃ₐ[S] B) : A ≃ₐ[R] B
{ commutes' := λ r, by { rw [algebra_map_apply R S A, algebra_map_apply R S B], exact f.commutes (algebra_map R S r) }, .. (f : A ≃+* B) }
def
alg_equiv.restrict_scalars
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra_map", "algebra_map_apply", "restrict_scalars" ]
R ⟶ S induces S-Alg ⥤ R-Alg
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_scalars_apply (f : A ≃ₐ[S] B) (x : A) : f.restrict_scalars R x = f x
rfl
lemma
alg_equiv.restrict_scalars_apply
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_restrict_scalars (f : A ≃ₐ[S] B) : (f.restrict_scalars R : A ≃+* B) = f
rfl
lemma
alg_equiv.coe_restrict_scalars
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_restrict_scalars' (f : A ≃ₐ[S] B) : (restrict_scalars R f : A → B) = f
rfl
lemma
alg_equiv.coe_restrict_scalars'
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "restrict_scalars" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_scalars_injective : function.injective (restrict_scalars R : (A ≃ₐ[S] B) → (A ≃ₐ[R] B))
λ f g h, alg_equiv.ext (alg_equiv.congr_fun h : _)
lemma
alg_equiv.restrict_scalars_injective
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "alg_equiv.congr_fun", "alg_equiv.ext", "restrict_scalars" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_scalars_span (hsur : function.surjective (algebra_map R A)) (X : set M) : restrict_scalars R (span A X) = span R X
begin refine ((span_le_restrict_scalars R A X).antisymm (λ m hm, _)).symm, refine span_induction hm subset_span (zero_mem _) (λ _ _, add_mem) (λ a m hm, _), obtain ⟨r, rfl⟩ := hsur a, simpa [algebra_map_smul] using smul_mem _ r hm end
lemma
submodule.restrict_scalars_span
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra_map", "algebra_map_smul", "restrict_scalars" ]
If `A` is an `R`-algebra such that the induced morphism `R →+* A` is surjective, then the `R`-module generated by a set `X` equals the `A`-module generated by `X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_span_eq_span_of_surjective (h : function.surjective (algebra_map R A)) (s : set M) : (submodule.span A s : set M) = submodule.span R s
congr_arg coe (submodule.restrict_scalars_span R A h s)
lemma
submodule.coe_span_eq_span_of_surjective
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra_map", "submodule.restrict_scalars_span", "submodule.span" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_mem_span_smul_of_mem {s : set S} {t : set A} {k : S} (hks : k ∈ span R s) {x : A} (hx : x ∈ t) : k • x ∈ span R (s • t)
span_induction hks (λ c hc, subset_span $ set.mem_smul.2 ⟨c, x, hc, hx, rfl⟩) (by { rw zero_smul, exact zero_mem _ }) (λ c₁ c₂ ih₁ ih₂, by { rw add_smul, exact add_mem ih₁ ih₂ }) (λ b c hc, by { rw is_scalar_tower.smul_assoc, exact smul_mem _ _ hc })
theorem
submodule.smul_mem_span_smul_of_mem
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "add_smul", "zero_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_mem_span_smul {s : set S} (hs : span R s = ⊤) {t : set A} {k : S} {x : A} (hx : x ∈ span R t) : k • x ∈ span R (s • t)
span_induction hx (λ x hx, smul_mem_span_smul_of_mem (hs.symm ▸ mem_top) hx) (by { rw smul_zero, exact zero_mem _ }) (λ x y ihx ihy, by { rw smul_add, exact add_mem ihx ihy }) (λ c x hx, smul_comm c k x ▸ smul_mem _ _ hx)
theorem
submodule.smul_mem_span_smul
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "smul_add", "smul_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_mem_span_smul' {s : set S} (hs : span R s = ⊤) {t : set A} {k : S} {x : A} (hx : x ∈ span R (s • t)) : k • x ∈ span R (s • t)
span_induction hx (λ x hx, let ⟨p, q, hp, hq, hpq⟩ := set.mem_smul.1 hx in by { rw [← hpq, smul_smul], exact smul_mem_span_smul_of_mem (hs.symm ▸ mem_top) hq }) (by { rw smul_zero, exact zero_mem _ }) (λ x y ihx ihy, by { rw smul_add, exact add_mem ihx ihy }) (λ c x hx, smul_comm c k x ▸ smul_mem _ _ hx)
theorem
submodule.smul_mem_span_smul'
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "smul_add", "smul_smul", "smul_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
span_smul_of_span_eq_top {s : set S} (hs : span R s = ⊤) (t : set A) : span R (s • t) = (span S t).restrict_scalars R
le_antisymm (span_le.2 $ λ x hx, let ⟨p, q, hps, hqt, hpqx⟩ := set.mem_smul.1 hx in hpqx ▸ (span S t).smul_mem p (subset_span hqt)) $ λ p hp, span_induction hp (λ x hx, one_smul S x ▸ smul_mem_span_smul hs (subset_span hx)) (zero_mem _) (λ _ _, add_mem) (λ k x hx, smul_mem_span_smul' hs hx)
theorem
submodule.span_smul_of_span_eq_top
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "one_smul", "restrict_scalars" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
span_algebra_map_image (a : set R) : submodule.span R (algebra_map R S '' a) = (submodule.span R a).map (algebra.linear_map R S)
(submodule.span_image $ algebra.linear_map R S).trans rfl
lemma
submodule.span_algebra_map_image
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra.linear_map", "algebra_map", "submodule.span", "submodule.span_image" ]
A variant of `submodule.span_image` for `algebra_map`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
span_algebra_map_image_of_tower {S T : Type*} [comm_semiring S] [semiring T] [module R S] [is_scalar_tower R S S] [algebra R T] [algebra S T] [is_scalar_tower R S T] (a : set S) : submodule.span R (algebra_map S T '' a) = (submodule.span R a).map ((algebra.linear_map S T).restrict_scalars R)
(submodule.span_image $ (algebra.linear_map S T).restrict_scalars R).trans rfl
lemma
submodule.span_algebra_map_image_of_tower
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra", "algebra.linear_map", "algebra_map", "comm_semiring", "is_scalar_tower", "module", "restrict_scalars", "semiring", "submodule.span", "submodule.span_image" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_mem_span_algebra_map_image {S T : Type*} [comm_semiring S] [semiring T] [algebra R S] [algebra R T] [algebra S T] [is_scalar_tower R S T] (x : S) (a : set S) (hx : x ∈ submodule.span R a) : algebra_map S T x ∈ submodule.span R (algebra_map S T '' a)
by { rw [span_algebra_map_image_of_tower, mem_map], exact ⟨x, hx, rfl⟩ }
lemma
submodule.map_mem_span_algebra_map_image
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "algebra", "algebra_map", "comm_semiring", "is_scalar_tower", "mem_map", "semiring", "submodule.span" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lsmul_injective [no_zero_smul_divisors A M] {x : A} (hx : x ≠ 0) : function.injective (lsmul R M x)
smul_right_injective _ hx
lemma
algebra.lsmul_injective
algebra.algebra
src/algebra/algebra/tower.lean
[ "algebra.algebra.equiv", "linear_algebra.span" ]
[ "no_zero_smul_divisors", "smul_right_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unitization (R A : Type*)
R × A
def
unitization
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[]
The minimal unitization of a non-unital `R`-algebra `A`. This is just a type synonym for `R × A`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl [has_zero A] (r : R) : unitization R A
(r, 0)
def
unitization.inl
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
The canonical inclusion `R → unitization R A`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst (x : unitization R A) : R
x.1
def
unitization.fst
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
The canonical projection `unitization R A → R`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
snd (x : unitization R A) : A
x.2
def
unitization.snd
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
The canonical projection `unitization R A → A`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ext {x y : unitization R A} (h1 : x.fst = y.fst) (h2 : x.snd = y.snd) : x = y
prod.ext h1 h2
lemma
unitization.ext
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "prod.ext", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst_inl [has_zero A] (r : R) : (inl r : unitization R A).fst = r
rfl
lemma
unitization.fst_inl
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
snd_inl [has_zero A] (r : R) : (inl r : unitization R A).snd = 0
rfl
lemma
unitization.snd_inl
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst_coe [has_zero R] (a : A) : (a : unitization R A).fst = 0
rfl
lemma
unitization.fst_coe
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
snd_coe [has_zero R] (a : A) : (a : unitization R A).snd = a
rfl
lemma
unitization.snd_coe
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_injective [has_zero A] : function.injective (inl : R → unitization R A)
function.left_inverse.injective $ fst_inl _
lemma
unitization.inl_injective
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_injective [has_zero R] : function.injective (coe : A → unitization R A)
function.left_inverse.injective $ snd_coe _
lemma
unitization.coe_injective
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst_zero [has_zero R] [has_zero A] : (0 : unitization R A).fst = 0
rfl
lemma
unitization.fst_zero
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
snd_zero [has_zero R] [has_zero A] : (0 : unitization R A).snd = 0
rfl
lemma
unitization.snd_zero
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst_add [has_add R] [has_add A] (x₁ x₂ : unitization R A) : (x₁ + x₂).fst = x₁.fst + x₂.fst
rfl
lemma
unitization.fst_add
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
snd_add [has_add R] [has_add A] (x₁ x₂ : unitization R A) : (x₁ + x₂).snd = x₁.snd + x₂.snd
rfl
lemma
unitization.snd_add
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst_neg [has_neg R] [has_neg A] (x : unitization R A) : (-x).fst = -x.fst
rfl
lemma
unitization.fst_neg
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
snd_neg [has_neg R] [has_neg A] (x : unitization R A) : (-x).snd = -x.snd
rfl
lemma
unitization.snd_neg
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst_smul [has_smul S R] [has_smul S A] (s : S) (x : unitization R A) : (s • x).fst = s • x.fst
rfl
lemma
unitization.fst_smul
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "has_smul", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
snd_smul [has_smul S R] [has_smul S A] (s : S) (x : unitization R A) : (s • x).snd = s • x.snd
rfl
lemma
unitization.snd_smul
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "has_smul", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_zero [has_zero R] [has_zero A] : (inl 0 : unitization R A) = 0
rfl
lemma
unitization.inl_zero
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_add [has_add R] [add_zero_class A] (r₁ r₂ : R) : (inl (r₁ + r₂) : unitization R A) = inl r₁ + inl r₂
ext rfl (add_zero 0).symm
lemma
unitization.inl_add
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_zero_class", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_neg [has_neg R] [add_group A] (r : R) : (inl (-r) : unitization R A) = -inl r
ext rfl neg_zero.symm
lemma
unitization.inl_neg
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_group", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_smul [monoid S] [add_monoid A] [has_smul S R] [distrib_mul_action S A] (s : S) (r : R) : (inl (s • r) : unitization R A) = s • inl r
ext rfl (smul_zero s).symm
lemma
unitization.inl_smul
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_monoid", "distrib_mul_action", "has_smul", "monoid", "smul_zero", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_zero [has_zero R] [has_zero A] : ↑(0 : A) = (0 : unitization R A)
rfl
lemma
unitization.coe_zero
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_add [add_zero_class R] [has_add A] (m₁ m₂ : A) : (↑(m₁ + m₂) : unitization R A) = m₁ + m₂
ext (add_zero 0).symm rfl
lemma
unitization.coe_add
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_zero_class", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_neg [add_group R] [has_neg A] (m : A) : (↑(-m) : unitization R A) = -m
ext neg_zero.symm rfl
lemma
unitization.coe_neg
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_group", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_smul [has_zero R] [has_zero S] [smul_with_zero S R] [has_smul S A] (r : S) (m : A) : (↑(r • m) : unitization R A) = r • m
ext (smul_zero _).symm rfl
lemma
unitization.coe_smul
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "has_smul", "smul_with_zero", "smul_zero", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_fst_add_coe_snd_eq [add_zero_class R] [add_zero_class A] (x : unitization R A) : inl x.fst + ↑x.snd = x
ext (add_zero x.1) (zero_add x.2)
lemma
unitization.inl_fst_add_coe_snd_eq
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_zero_class", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ind {R A} [add_zero_class R] [add_zero_class A] {P : unitization R A → Prop} (h : ∀ (r : R) (a : A), P (inl r + a)) (x) : P x
inl_fst_add_coe_snd_eq x ▸ h x.1 x.2
lemma
unitization.ind
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_zero_class", "unitization" ]
To show a property hold on all `unitization R A` it suffices to show it holds on terms of the form `inl r + a`. This can be used as `induction x using unitization.ind`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_map_ext {N} [semiring S] [add_comm_monoid R] [add_comm_monoid A] [add_comm_monoid N] [module S R] [module S A] [module S N] ⦃f g : unitization R A →ₗ[S] N⦄ (hl : ∀ r, f (inl r) = g (inl r)) (hr : ∀ a : A, f a = g a) : f = g
linear_map.prod_ext (linear_map.ext hl) (linear_map.ext hr)
lemma
unitization.linear_map_ext
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_comm_monoid", "linear_map.ext", "linear_map.prod_ext", "module", "semiring", "unitization" ]
This cannot be marked `@[ext]` as it ends up being used instead of `linear_map.prod_ext` when working with `R × A`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_hom [semiring R] [add_comm_monoid A] [module R A] : A →ₗ[R] unitization R A
{ to_fun := coe, ..linear_map.inr R R A }
def
unitization.coe_hom
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_comm_monoid", "linear_map.inr", "module", "semiring", "unitization" ]
The canonical `R`-linear inclusion `A → unitization R A`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
snd_hom [semiring R] [add_comm_monoid A] [module R A] : unitization R A →ₗ[R] A
{ to_fun := snd, ..linear_map.snd _ _ _ }
def
unitization.snd_hom
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_comm_monoid", "linear_map.snd", "module", "semiring", "unitization" ]
The canonical `R`-linear projection `unitization R A → A`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst_one [has_one R] [has_zero A] : (1 : unitization R A).fst = 1
rfl
lemma
unitization.fst_one
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
snd_one [has_one R] [has_zero A] : (1 : unitization R A).snd = 0
rfl
lemma
unitization.snd_one
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst_mul [has_mul R] [has_add A] [has_mul A] [has_smul R A] (x₁ x₂ : unitization R A) : (x₁ * x₂).fst = x₁.fst * x₂.fst
rfl
lemma
unitization.fst_mul
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "has_smul", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
snd_mul [has_mul R] [has_add A] [has_mul A] [has_smul R A] (x₁ x₂ : unitization R A) : (x₁ * x₂).snd = x₁.fst • x₂.snd + x₂.fst • x₁.snd + x₁.snd * x₂.snd
rfl
lemma
unitization.snd_mul
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "has_smul", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_one [has_one R] [has_zero A] : (inl 1 : unitization R A) = 1
rfl
lemma
unitization.inl_one
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_mul [monoid R] [non_unital_non_assoc_semiring A] [distrib_mul_action R A] (r₁ r₂ : R) : (inl (r₁ * r₂) : unitization R A) = inl r₁ * inl r₂
ext rfl $ show (0 : A) = r₁ • (0 : A) + r₂ • 0 + 0 * 0, by simp only [smul_zero, add_zero, mul_zero]
lemma
unitization.inl_mul
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "distrib_mul_action", "monoid", "mul_zero", "non_unital_non_assoc_semiring", "smul_zero", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_mul_inl [monoid R] [non_unital_non_assoc_semiring A] [distrib_mul_action R A] (r₁ r₂ : R) : (inl r₁ * inl r₂ : unitization R A) = inl (r₁ * r₂)
(inl_mul A r₁ r₂).symm
lemma
unitization.inl_mul_inl
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "distrib_mul_action", "monoid", "non_unital_non_assoc_semiring", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_mul [semiring R] [add_comm_monoid A] [has_mul A] [smul_with_zero R A] (a₁ a₂ : A) : (↑(a₁ * a₂) : unitization R A) = a₁ * a₂
ext (mul_zero _).symm $ show a₁ * a₂ = (0 : R) • a₂ + (0 : R) • a₁ + a₁ * a₂, by simp only [zero_smul, zero_add]
lemma
unitization.coe_mul
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_comm_monoid", "mul_zero", "semiring", "smul_with_zero", "unitization", "zero_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_mul_coe [semiring R] [non_unital_non_assoc_semiring A] [distrib_mul_action R A] (r : R) (a : A) : (inl r * a : unitization R A) = ↑(r • a)
ext (mul_zero r) $ show r • a + (0 : R) • 0 + 0 * a = r • a, by rw [smul_zero, add_zero, zero_mul, add_zero]
lemma
unitization.inl_mul_coe
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "distrib_mul_action", "mul_zero", "non_unital_non_assoc_semiring", "semiring", "smul_zero", "unitization", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_mul_inl [semiring R] [non_unital_non_assoc_semiring A] [distrib_mul_action R A] (r : R) (a : A) : (a * inl r : unitization R A) = ↑(r • a)
ext (zero_mul r) $ show (0 : R) • 0 + r • a + a * 0 = r • a, by rw [smul_zero, zero_add, mul_zero, add_zero]
lemma
unitization.coe_mul_inl
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "distrib_mul_action", "mul_zero", "non_unital_non_assoc_semiring", "semiring", "smul_zero", "unitization", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_one_class [monoid R] [non_unital_non_assoc_semiring A] [distrib_mul_action R A] : mul_one_class (unitization R A)
{ one_mul := λ x, ext (one_mul x.1) $ show (1 : R) • x.2 + x.1 • 0 + 0 * x.2 = x.2, by rw [one_smul, smul_zero, add_zero, zero_mul, add_zero], mul_one := λ x, ext (mul_one x.1) $ show (x.1 • 0 : A) + (1 : R) • x.2 + x.2 * 0 = x.2, by rw [smul_zero, zero_add, one_smul, mul_zero, add_zero], .. unitization.has...
instance
unitization.mul_one_class
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "distrib_mul_action", "monoid", "mul_one", "mul_one_class", "mul_zero", "non_unital_non_assoc_semiring", "one_mul", "one_smul", "smul_zero", "unitization", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_ring_hom [semiring R] [non_unital_semiring A] [module R A] : R →+* unitization R A
{ to_fun := inl, map_one' := inl_one A, map_mul' := inl_mul A, map_zero' := inl_zero A, map_add' := inl_add A }
def
unitization.inl_ring_hom
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "module", "non_unital_semiring", "semiring", "unitization" ]
The canonical inclusion of rings `R →+* unitization R A`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst_star [has_star R] [has_star A] (x : unitization R A) : (star x).fst = star x.fst
rfl
lemma
unitization.fst_star
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "has_star", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
snd_star [has_star R] [has_star A] (x : unitization R A) : (star x).snd = star x.snd
rfl
lemma
unitization.snd_star
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "has_star", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_star [has_star R] [add_monoid A] [star_add_monoid A] (r : R) : inl (star r) = star (inl r : unitization R A)
ext rfl (by simp only [snd_star, star_zero, snd_inl])
lemma
unitization.inl_star
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_monoid", "has_star", "star_add_monoid", "star_zero", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_star [add_monoid R] [star_add_monoid R] [has_star A] (a : A) : ↑(star a) = star (a : unitization R A)
ext (by simp only [fst_star, star_zero, fst_coe]) rfl
lemma
unitization.coe_star
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "add_monoid", "has_star", "star_add_monoid", "star_zero", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
algebra : algebra S (unitization R A)
{ commutes' := λ r x, begin induction x using unitization.ind, simp only [mul_add, add_mul, ring_hom.to_fun_eq_coe, ring_hom.coe_comp, function.comp_app, inl_ring_hom_apply, inl_mul_inl], rw [inl_mul_coe, coe_mul_inl, mul_comm] end, smul_def' := λ s x, begin induction x using unitization.i...
instance
unitization.algebra
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "algebra", "algebra.algebra_map_eq_smul_one", "algebra_map", "mul_comm", "ring_hom.coe_comp", "ring_hom.to_fun_eq_coe", "smul_add", "smul_one_mul", "smul_one_smul", "unitization", "unitization.ind", "unitization.inl_ring_hom" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
algebra_map_eq_inl_comp : ⇑(algebra_map S (unitization R A)) = inl ∘ algebra_map S R
rfl
lemma
unitization.algebra_map_eq_inl_comp
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "algebra_map", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
algebra_map_eq_inl_ring_hom_comp : algebra_map S (unitization R A) = (inl_ring_hom R A).comp (algebra_map S R)
rfl
lemma
unitization.algebra_map_eq_inl_ring_hom_comp
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "algebra_map", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
algebra_map_eq_inl : ⇑(algebra_map R (unitization R A)) = inl
rfl
lemma
unitization.algebra_map_eq_inl
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "algebra_map", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
algebra_map_eq_inl_hom : algebra_map R (unitization R A) = inl_ring_hom R A
rfl
lemma
unitization.algebra_map_eq_inl_hom
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "algebra_map", "unitization" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst_hom : unitization R A →ₐ[R] R
{ to_fun := fst, map_one' := fst_one, map_mul' := fst_mul, map_zero' := fst_zero, map_add' := fst_add, commutes' := fst_inl A }
def
unitization.fst_hom
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "unitization" ]
The canonical `R`-algebra projection `unitization R A → R`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_non_unital_alg_hom (R A : Type*) [comm_semiring R] [non_unital_semiring A] [module R A] : A →ₙₐ[R] unitization R A
{ to_fun := coe, map_smul' := coe_smul R, map_zero' := coe_zero R, map_add' := coe_add R, map_mul' := coe_mul R }
def
unitization.coe_non_unital_alg_hom
algebra.algebra
src/algebra/algebra/unitization.lean
[ "algebra.algebra.basic", "linear_algebra.prod", "algebra.hom.non_unital_alg" ]
[ "comm_semiring", "module", "non_unital_semiring", "unitization" ]
The coercion from a non-unital `R`-algebra `A` to its unitization `unitization R A` realized as a non-unital algebra homomorphism.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83