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Tweaks
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grunweg committed Dec 12, 2024
1 parent 2b496b4 commit f15b416
Showing 1 changed file with 7 additions and 7 deletions.
14 changes: 7 additions & 7 deletions Mathlib/Topology/Category/DeltaGenerated.lean
Original file line number Diff line number Diff line change
Expand Up @@ -26,15 +26,15 @@ open CategoryTheory

/-- The type of delta-generated topological spaces. -/
structure DeltaGenerated where
/-- The underlying topological space. -/
/-- the underlying topological space -/
toTop : TopCat.{u}
/-- The underlying topological space is delta-generated. -/
deltaGenerated : DeltaGeneratedSpace toTop := by infer_instance

namespace DeltaGenerated

instance : CoeSort DeltaGenerated Type* :=
fun X => X.toTop⟩
fun X X.toTop⟩

attribute [instance] deltaGenerated

Expand All @@ -44,12 +44,12 @@ instance : LargeCategory.{u} DeltaGenerated.{u} :=
instance : ConcreteCategory.{u} DeltaGenerated.{u} :=
InducedCategory.concreteCategory _

/-- Constructor for objects of the category `DeltaGenerated`. -/
/-- Constructor for objects of the category `DeltaGenerated` -/
def of (X : Type u) [TopologicalSpace X] [DeltaGeneratedSpace X] : DeltaGenerated.{u} where
toTop := TopCat.of X
deltaGenerated := ‹_›

/-- The forgetful functor `DeltaGenerated ⥤ TopCat`. -/
/-- The forgetful functor `DeltaGenerated ⥤ TopCat` -/
@[simps!]
def deltaGeneratedToTop : DeltaGenerated.{u} ⥤ TopCat.{u} :=
inducedFunctor _
Expand All @@ -67,7 +67,7 @@ instance : deltaGeneratedToTop.{u}.Faithful := fullyFaithfulDeltaGeneratedToTop.
@[simps!]
def topToDeltaGenerated : TopCat.{u} ⥤ DeltaGenerated.{u} where
obj X := of (DeltaGeneratedSpace.of X)
map {_ Y} f := ⟨f,(continuous_to_deltaGenerated (Y := Y)).mpr <|
map {_ Y} f := ⟨f, (continuous_to_deltaGenerated (Y := Y)).mpr <|
continuous_le_dom deltaGenerated_le f.continuous⟩

instance : topToDeltaGenerated.{u}.Faithful :=
Expand All @@ -77,9 +77,9 @@ instance : topToDeltaGenerated.{u}.Faithful :=
def coreflectorAdjunction : deltaGeneratedToTop ⊣ topToDeltaGenerated :=
Adjunction.mkOfUnitCounit {
unit := {
app := fun X => ⟨id, continuous_iff_coinduced_le.mpr (eq_deltaGenerated (X := X)).le⟩ }
app X := ⟨id, continuous_iff_coinduced_le.mpr (eq_deltaGenerated (X := X)).le⟩ }
counit := {
app := fun X => ⟨DeltaGeneratedSpace.counit, DeltaGeneratedSpace.continuous_counit⟩ }}
app X := ⟨DeltaGeneratedSpace.counit, DeltaGeneratedSpace.continuous_counit⟩ }}

/-- The category of delta-generated spaces is coreflective in the category of topological spaces. -/
instance deltaGeneratedToTop.coreflective : Coreflective deltaGeneratedToTop where
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