map
and comap
for Submodule
s #
Main declarations #
Submodule.map
: The pushforward of a submodulep ⊆ M
byf : M → M₂
Submodule.comap
: The pullback of a submodulep ⊆ M₂
alongf : M → M₂
Submodule.giMapComap
:map f
andcomap f
form aGaloisInsertion
whenf
is surjective.Submodule.gciMapComap
:map f
andcomap f
form aGaloisCoinsertion
whenf
is injective.
Tags #
submodule, subspace, linear map, pushforward, pullback
The pushforward of a submodule p ⊆ M
by f : M → M₂
Equations
- Submodule.map f p = let __src := AddSubmonoid.map f p.toAddSubmonoid; { carrier := ⇑f '' ↑p, add_mem' := ⋯, zero_mem' := ⋯, smul_mem' := ⋯ }
Instances For
The pushforward of a submodule by an injective linear map is
linearly equivalent to the original submodule. See also LinearEquiv.submoduleMap
for a
computable version when f
has an explicit inverse.
Equations
- Submodule.equivMapOfInjective f i p = let __src := Equiv.Set.image (⇑f) (↑p) i; { toFun := __src.toFun, map_add' := ⋯, map_smul' := ⋯, invFun := __src.invFun, left_inv := ⋯, right_inv := ⋯ }
Instances For
The pullback of a submodule p ⊆ M₂
along f : M → M₂
Equations
- Submodule.comap f p = let __src := AddSubmonoid.comap f p.toAddSubmonoid; { carrier := ⇑f ⁻¹' ↑p, add_mem' := ⋯, zero_mem' := ⋯, smul_mem' := ⋯ }
Instances For
map f
and comap f
form a GaloisInsertion
when f
is surjective.
Equations
- Submodule.giMapComap hf = ⋯.toGaloisInsertion ⋯
Instances For
map f
and comap f
form a GaloisCoinsertion
when f
is injective.
Equations
- Submodule.gciMapComap hf = ⋯.toGaloisCoinsertion ⋯
Instances For
A linear isomorphism induces an order isomorphism of submodules.
Equations
- Submodule.orderIsoMapComapOfBijective f hf = { toFun := Submodule.map f, invFun := Submodule.comap f, left_inv := ⋯, right_inv := ⋯, map_rel_iff' := ⋯ }
Instances For
A linear isomorphism induces an order isomorphism of submodules.
Equations
Instances For
The infimum of a family of invariant submodule of an endomorphism is also an invariant submodule.
If s ≤ t
, then we can view s
as a submodule of t
by taking the comap
of t.subtype
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Given modules M
, M₂
over a commutative ring, together with submodules p ⊆ M
, q ⊆ M₂
,
the set of maps $\{f ∈ Hom(M, M₂) | f(p) ⊆ q \}$ is a submodule of Hom(M, M₂)
.
Equations
- pₗ.compatibleMaps qₗ = { carrier := {fₗ : N →ₗ[R] N₂ | pₗ ≤ Submodule.comap fₗ qₗ}, add_mem' := ⋯, zero_mem' := ⋯, smul_mem' := ⋯ }
Instances For
A linear map between two modules restricts to a linear map from any submodule p of the domain onto the image of that submodule.
This is the linear version of AddMonoidHom.addSubmonoidMap
and AddMonoidHom.addSubgroupMap
.
Equations
- f.submoduleMap p = f.restrict ⋯
Instances For
Linear equivalences #
A linear equivalence of two modules restricts to a linear equivalence from any submodule
p
of the domain onto the image of that submodule.
This is the linear version of AddEquiv.submonoidMap
and AddEquiv.subgroupMap
.
This is LinearEquiv.ofSubmodule'
but with map
on the right instead of comap
on the left.
Equations
- One or more equations did not get rendered due to their size.