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Structures · Category theory

CategoryTheory.IsConnected

We define a connected category as a _nonempty_ category for which every functor to a discrete category is constant. NB. Some authors include the empty category as connected, we do not. We instead are interested in categories with exactly one 'connected component'. This allows us to show that the functor X ⨯ - preserves connected limits.

Defined in
Mathlib.CategoryTheory.IsConnected
Shape
One type argument · adds is_nonempty

Extends1

Extended by0

Nothing extends this class yet.

Forgetful instances

Every CategoryTheory.IsConnected is also a

Concrete types that are instances13

  • CategoryTheory.Comma
  • CategoryTheory.CostructuredArrow
  • CategoryTheory.StructuredArrow
  • CategoryTheory.ULiftHom
  • CategoryTheory.ActionCategory
  • CategoryTheory.LocalizerMorphism.LeftResolution
  • CategoryTheory.LocalizerMorphism.RightResolution
  • CategoryTheory.Limits.WalkingParallelPair
  • CategoryTheory.Limits.WidePullbackShape
  • CategoryTheory.Limits.WidePushoutShape
  • CategoryTheory.ConnectedComponents.Component
  • Prod
  • Opposite

How is a type an instance?

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Assumed by71

Ancestors2