Module

TopCatCompat.lean

Nyll.EtaleFundamentalGroups.ContinuousActions.TopCatCompat
4 declarations indexed from sourceView source ↗

The identity forgetful functor on TopCat

HasForget₂ deliberately has no general self-instance. The continuous-action API nevertheless needs the canonical identity forgetful functor when its ambient concrete category is TopCat itself.

Declarations

CategoryTheory.topCatHasForget₂Self

The canonical identity forgetful functor from TopCat to itself.

Source context 4 commands

Surrounding namespaces, section variables, and local commands at this declaration.

@[expose] public section
open CategoryTheory
namespace CategoryTheory
universe u v
instance topCatHasForget₂Self : HasForget₂ TopCat.{u} TopCat.{u} where
  forget₂ := 𝟭 TopCat.{u}
CategoryTheory.DiscreteContAction.topCatConcrete
Source context 5 commands

Surrounding namespaces, section variables, and local commands at this declaration.

@[expose] public section
open CategoryTheory
namespace CategoryTheory
universe u v
namespace DiscreteContAction

-- `DiscreteContAction` is a non-reducible full subcategory in mathlib.  Make
-- its canonical concrete and forgetful instances available for `TopCat`
-- without relying on consumers unfolding that definition during search.
instance topCatConcrete {G : Type v} [Monoid G] [TopologicalSpace G] :
    ConcreteCategory (DiscreteContAction TopCat.{u} G)
      (fun S T => Action.HomSubtype TopCat.{u} G S.obj.obj T.obj.obj) := by
  exact ObjectProperty.FullSubcategory.concreteCategory
    (ContAction.IsDiscrete (V := TopCat.{u}) (G := G))
CategoryTheory.DiscreteContAction.topCatHasForget₂
Source context 5 commands

Surrounding namespaces, section variables, and local commands at this declaration.

@[expose] public section
open CategoryTheory
namespace CategoryTheory
universe u v
namespace DiscreteContAction

-- `DiscreteContAction` is a non-reducible full subcategory in mathlib.  Make
-- its canonical concrete and forgetful instances available for `TopCat`
-- without relying on consumers unfolding that definition during search.
instance topCatHasForget₂ {G : Type v} [Monoid G] [TopologicalSpace G] :
    HasForget₂ (DiscreteContAction TopCat.{u} G) TopCat.{u}
CategoryTheory.DiscreteContAction.carrierMulAction

The carrier of a discrete continuous TopCat-action has the original multiplicative action.

Source context 5 commands

Surrounding namespaces, section variables, and local commands at this declaration.

@[expose] public section
open CategoryTheory
namespace CategoryTheory
universe u v
namespace DiscreteContAction

-- `DiscreteContAction` is a non-reducible full subcategory in mathlib.  Make
-- its canonical concrete and forgetful instances available for `TopCat`
-- without relying on consumers unfolding that definition during search.
instance carrierMulAction {G : Type v} [Monoid G] [TopologicalSpace G]
    (S : DiscreteContAction TopCat.{u} G) :
    MulAction G
      ((forget₂ (DiscreteContAction TopCat.{u} G) TopCat.{u}).obj S)