Algebra structure on monoid algebras #
Multiplicative monoids #
Non-unital, non-associative algebra structure #
A non-unital R-algebra homomorphism from R[M] is uniquely defined by its
values on the monomials single a 1.
A non-unital R-algebra homomorphism from R[M] is uniquely defined by its
values on the monomials single a 1.
See note [partially-applied ext lemmas].
The functor M ↦ R[M], from the category of magmas to the category of non-unital,
non-associative algebras over R is adjoint to the forgetful functor in the other direction.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Algebra structure #
The instance Algebra R A[M] whenever we have Algebra R A.
In particular this provides the instance Algebra R R[M].
Equations
- MonoidAlgebra.algebra = { toSMul := MonoidAlgebra.smulZeroClass.toSMul, algebraMap := MonoidAlgebra.singleOneRingHom.comp (algebraMap R A), commutes' := ⋯, smul_def' := ⋯ }
The instance Algebra R R[M] whenever we have Algebra R R.
In particular this provides the instance Algebra R R[M].
Equations
- AddMonoidAlgebra.algebra = { toSMul := AddMonoidAlgebra.smulZeroClass.toSMul, algebraMap := AddMonoidAlgebra.singleZeroRingHom.comp (algebraMap R A), commutes' := ⋯, smul_def' := ⋯ }
MonoidAlgebra.single 1 as an AlgHom
Equations
- MonoidAlgebra.singleOneAlgHom = { toRingHom := MonoidAlgebra.singleOneRingHom, commutes' := ⋯ }
Instances For
AddMonoidAlgebra.single 0 as an AlgHom
Equations
- AddMonoidAlgebra.singleZeroAlgHom = { toRingHom := AddMonoidAlgebra.singleZeroRingHom, commutes' := ⋯ }
Instances For
liftNCRingHom as an AlgHom, for when f is an AlgHom
Equations
- MonoidAlgebra.liftNCAlgHom f g h_comm = { toRingHom := MonoidAlgebra.liftNCRingHom (↑f) g h_comm, commutes' := ⋯ }
Instances For
A R-algebra homomorphism from R[M] is uniquely defined by its
values on the functions single a 1.
A R-algebra homomorphism from R[M] is uniquely defined by its
values on the functions single a 1.
Any monoid homomorphism M →* A can be lifted to an algebra homomorphism R[M] →ₐ[R] A.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Decomposition of a R-algebra homomorphism from R[M] by
its values on F (single a 1).
If f : M → N is a homomorphism between two magmas, then MonoidAlgebra.mapDomain f
is a non-unital algebra homomorphism between their magma algebras.
Equations
- MonoidAlgebra.mapDomainNonUnitalAlgHom R A f = { toFun := (MonoidAlgebra.mapDomainNonUnitalRingHom A f).toFun, map_smul' := ⋯, map_zero' := ⋯, map_add' := ⋯, map_mul' := ⋯ }
Instances For
If f : M → N is a homomorphism between two additive magmas,
then AddMonoidAlgebra.mapDomain f is a non-unital algebra homomorphism
between their additive magma algebras.
Equations
- AddMonoidAlgebra.mapDomainNonUnitalAlgHom R A f = { toFun := (AddMonoidAlgebra.mapDomainNonUnitalRingHom A f).toFun, map_smul' := ⋯, map_zero' := ⋯, map_add' := ⋯, map_mul' := ⋯ }
Instances For
If f : M → N is a monoid homomorphism, then MonoidAlgebra.mapDomain f is an algebra
homomorphism between their monoid algebras.
Equations
- MonoidAlgebra.mapDomainAlgHom R A f = { toRingHom := MonoidAlgebra.mapDomainRingHom A f, commutes' := ⋯ }
Instances For
If f : M → N is an additive monoid homomorphism, then MonoidAlgebra.mapDomain f is an
algebra homomorphism between their additive monoid algebras.
Equations
- AddMonoidAlgebra.mapDomainAlgHom R A f = { toRingHom := AddMonoidAlgebra.mapDomainRingHom A f, commutes' := ⋯ }
Instances For
If e : M ≃* N is a multiplicative equivalence between two monoids, then
MonoidAlgebra.domCongr e is an algebra equivalence between their monoid algebras.
Equations
- MonoidAlgebra.domCongr R A e = { toEquiv := (MonoidAlgebra.mapDomainRingEquiv A e).toEquiv, map_mul' := ⋯, map_add' := ⋯, commutes' := ⋯ }
Instances For
If e : M ≃+ N is an additive equivalence between two additive monoids, then
AddMonoidAlgebra.domCongr e is an algebra equivalence between their additive monoid algebras.
Equations
- AddMonoidAlgebra.domCongr R A e = { toEquiv := (AddMonoidAlgebra.mapDomainRingEquiv A e).toEquiv, map_mul' := ⋯, map_add' := ⋯, commutes' := ⋯ }
Instances For
The algebra homomorphism of monoid algebras induced by a homomorphism of the base algebras.
Equations
- MonoidAlgebra.mapRangeAlgHom M f = { toRingHom := MonoidAlgebra.mapRangeRingHom M ↑f, commutes' := ⋯ }
Instances For
The algebra homomorphism of additive monoid algebras induced by a homomorphism of the base algebras.
Equations
- AddMonoidAlgebra.mapRangeAlgHom M f = { toRingHom := AddMonoidAlgebra.mapRangeRingHom M ↑f, commutes' := ⋯ }
Instances For
The algebra isomorphism of monoid algebras induced by an isomorphism of the base algebras.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The algebra isomorphism of additive monoid algebras induced by an isomorphism of the base algebras.
Equations
- One or more equations did not get rendered due to their size.
Instances For
When V is a R[M]-module, multiplication by a group element g is a R-linear map.
Equations
- MonoidAlgebra.GroupSMul.linearMap R V g = { toFun := fun (v : V) => MonoidAlgebra.single g 1 • v, map_add' := ⋯, map_smul' := ⋯ }
Instances For
Build a R[M]-linear map from a R-linear map and evidence that it is M-equivariant.
Equations
- MonoidAlgebra.equivariantOfLinearOfComm f h = { toFun := ⇑f, map_add' := ⋯, map_smul' := ⋯ }
Instances For
If S is an R-algebra, then S[M] is a R[M] algebra.
Warning: This produces a diamond for Algebra R[M] S[M][M] and another one for Algebra R[M] R[M].
That's why it is not a global instance.
Equations
Instances For
If S is an R-algebra, then S[M] is an R[M]-algebra.
Warning: This produces a diamond for Algebra R[M] S[M][M] and another one for Algebra R[M] R[M].
That's why it is not a global instance.
Equations
Instances For
Non-unital, non-associative algebra structure #
See note [partially-applied ext lemmas].
The functor M ↦ R[M], from the category of magmas to the category of
non-unital, non-associative algebras over R is adjoint to the forgetful functor in the other
direction.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Algebra structure #
liftNCRingHom as an AlgHom, for when f is an AlgHom
Equations
- AddMonoidAlgebra.liftNCAlgHom f g h_comm = { toRingHom := AddMonoidAlgebra.liftNCRingHom (↑f) g h_comm, commutes' := ⋯ }
Instances For
Any monoid homomorphism M →* A can be lifted to an algebra homomorphism
R[M] →ₐ[R] A.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Decomposition of a R-algebra homomorphism from R[M] by
its values on F (single a 1).
The algebra equivalence between AddMonoidAlgebra and MonoidAlgebra in terms of
Multiplicative.
Equations
- AddMonoidAlgebra.toMultiplicativeAlgEquiv A M = { toEquiv := (AddMonoidAlgebra.toMultiplicative A M).toEquiv, map_mul' := ⋯, map_add' := ⋯, commutes' := ⋯ }
Instances For
The algebra equivalence between MonoidAlgebra and AddMonoidAlgebra in terms of
Additive.
Equations
- MonoidAlgebra.toAdditiveAlgEquiv A M = { toEquiv := (MonoidAlgebra.toAdditive A M).toEquiv, map_mul' := ⋯, map_add' := ⋯, commutes' := ⋯ }