English
The forgetful functor from BialgCat to AlgCat inherits a monoidal structure, i.e., it can be promoted to a monoidal functor between the respective forgetful contexts.
Русский
Забывающий функтор из BialgCat в AlgCat наследует монодическую структуру и представляет собой моноидальный функтор между соответствующими забывательными контекстами.
LaTeX
$$$(forget₂(\mathrm{BialgCat}\, R)\, \mathrm{toAlgCat}\, R)\;\text{ is Monoidal}$$$
Lean4
/-- The data needed to induce a `MonoidalCategory` structure via
`BialgCat.instMonoidalCategoryStruct` and the forgetful functor to algebras. -/
@[simps]
noncomputable def inducingFunctorData : Monoidal.InducingFunctorData (forget₂ (BialgCat R) (AlgCat R))
where
μIso _ _ := Iso.refl _
whiskerLeft_eq _ _ _ _ := by ext; rfl
whiskerRight_eq _ _ := by ext; rfl
tensorHom_eq _ _ := by ext; rfl
εIso := Iso.refl _
associator_eq _ _
_ :=
AlgCat.hom_ext _ <| Algebra.TensorProduct.ext (Algebra.TensorProduct.ext (by ext; rfl) (by ext; rfl)) (by ext; rfl)
leftUnitor_eq _ := AlgCat.hom_ext _ <| Algebra.TensorProduct.ext rfl (by ext; rfl)
rightUnitor_eq _ := AlgCat.hom_ext _ <| Algebra.TensorProduct.ext (by ext; rfl) rfl