Homomorphisms of R
-coalgebras #
This file defines bundled homomorphisms of R
-coalgebras. We largely mimic
Mathlib/Algebra/Algebra/Hom.lean
.
Main definitions #
CoalgHom R A B
: the type ofR
-coalgebra morphisms fromA
toB
.Coalgebra.counitCoalgHom R A : A →ₗc[R] R
: the counit of a coalgebra as a coalgebra homomorphism.
Notations #
A →ₗc[R] B
:R
-coalgebra homomorphism fromA
toB
.
Given R
-modules A, B
with comultiplication maps Δ_A, Δ_B
and counit maps
ε_A, ε_B
, an R
-coalgebra homomorphism A →ₗc[R] B
is an R
-linear map f
such that
ε_B ∘ f = ε_A
and (f ⊗ f) ∘ Δ_A = Δ_B ∘ f
.
- toFun : A → B
- map_smul' : ∀ (m : R) (x : A), self.toFun (m • x) = (RingHom.id R) m • self.toFun x
- counit_comp : Coalgebra.counit ∘ₗ self.toLinearMap = Coalgebra.counit
- map_comp_comul : TensorProduct.map self.toLinearMap self.toLinearMap ∘ₗ Coalgebra.comul = Coalgebra.comul ∘ₗ self.toLinearMap
Instances For
Given R
-modules A, B
with comultiplication maps Δ_A, Δ_B
and counit maps
ε_A, ε_B
, an R
-coalgebra homomorphism A →ₗc[R] B
is an R
-linear map f
such that
ε_B ∘ f = ε_A
and (f ⊗ f) ∘ Δ_A = Δ_B ∘ f
.
Equations
- «term_→ₗc_» = Lean.ParserDescr.trailingNode `«term_→ₗc_» 25 26 (Lean.ParserDescr.binary `andthen (Lean.ParserDescr.symbol " →ₗc ") (Lean.ParserDescr.cat `term 25))
Instances For
Given R
-modules A, B
with comultiplication maps Δ_A, Δ_B
and counit maps
ε_A, ε_B
, an R
-coalgebra homomorphism A →ₗc[R] B
is an R
-linear map f
such that
ε_B ∘ f = ε_A
and (f ⊗ f) ∘ Δ_A = Δ_B ∘ f
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
CoalgHomClass F R A B
asserts F
is a type of bundled coalgebra homomorphisms
from A
to B
.
- map_smulₛₗ : ∀ (f : F) (c : R) (x : A), f (c • x) = (RingHom.id R) c • f x
- counit_comp : ∀ (f : F), Coalgebra.counit ∘ₗ ↑f = Coalgebra.counit
- map_comp_comul : ∀ (f : F), TensorProduct.map ↑f ↑f ∘ₗ Coalgebra.comul = Coalgebra.comul ∘ₗ ↑f
Instances
Turn an element of a type F
satisfying CoalgHomClass F R A B
into an actual
CoalgHom
. This is declared as the default coercion from F
to A →ₗc[R] B
.
Equations
- ↑f = { toFun := ⇑f, map_add' := ⋯, map_smul' := ⋯, counit_comp := ⋯, map_comp_comul := ⋯ }
Instances For
Equations
- CoalgHomClass.instCoeToCoalgHom = { coe := CoalgHomClass.toCoalgHom }
Equations
- ⋯ = ⋯
See Note [custom simps projection]
Equations
- CoalgHom.Simps.apply f = ⇑f
Instances For
Copy of a CoalgHom
with a new toFun
equal to the old one. Useful to fix definitional
equalities.
Equations
- f.copy f' h = { toLinearMap := (↑f).copy f' h, counit_comp := ⋯, map_comp_comul := ⋯ }
Instances For
Identity map as a CoalgHom
.
Equations
- CoalgHom.id R A = { toLinearMap := LinearMap.id, counit_comp := ⋯, map_comp_comul := ⋯ }
Instances For
Composition of coalgebra homomorphisms.
Equations
- φ₁.comp φ₂ = { toLinearMap := ↑φ₁ ∘ₗ ↑φ₂, counit_comp := ⋯, map_comp_comul := ⋯ }
Instances For
The counit of a coalgebra as a CoalgHom
.
Equations
- Coalgebra.counitCoalgHom R A = { toLinearMap := Coalgebra.counit, counit_comp := ⋯, map_comp_comul := ⋯ }
Instances For
Equations
- ⋯ = ⋯
If φ : A → B
is a coalgebra map and a = ∑ xᵢ ⊗ yᵢ
, then φ a = ∑ φ xᵢ ⊗ φ yᵢ
Equations
- repr.induced φ = Coalgebra.Repr.mk repr.index (⇑φ ∘ repr.left) (⇑φ ∘ repr.right) ⋯