The associator for actions of bifunctors on graded objects #
Given functors F₁₂ : C₁ ⥤ C₂ ⥤ C₁₂
, G : C₁₂ ⥤ C₃ ⥤ C₄
,
F : C₁ ⥤ C₂₃ ⥤ C₄
, G₂₃ : C₂ ⥤ C₃ ⥤ C₂₃
equipped with an isomorphism
associator : bifunctorComp₁₂ F₁₂ G ≅ bifunctorComp₂₃ F G₂₃
(which informally means
that we have natural isomorphisms G(F₁₂(X₁, X₂), X₃) ≅ F(X₁, G₂₃(X₂, X₃))
),
a map r : I₁ × I₂ × I₃ → J
, and data ρ₁₂ : BifunctorComp₁₂IndexData r
and
ρ₂₃ : BifunctorComp₂₃IndexData r
, then if X₁ : GradedObject I₁ C₁
,
X₂ : GradedObject I₂ C₂
and X₃ : GradedObject I₃ C₃
satisfy suitable assumptions, we construct an isomorphism
mapBifunctorAssociator associator ρ₁₂ ρ₂₃ X₁ X₂ X₃
between
mapBifunctorMapObj G ρ₁₂.q (mapBifunctorMapObj F₁₂ ρ₁₂.p X₁ X₂) X₃
and
mapBifunctorMapObj F ρ₂₃.q X₁ (mapBifunctorMapObj G₂₃ ρ₂₃.p X₂ X₃)
in the category
GradedObject J C₄
.
This construction shall be used in the definition of the monoidal category structure on graded objects indexed by an additive monoid.
Associator isomorphism for the action of bifunctors on graded objects.
Equations
- One or more equations did not get rendered due to their size.