CatDat

walking isomorphism

  • notation: {01}\{0 \rightleftarrows 1\}
  • objects: two objects 00 and 11
  • morphisms: identities, and two morphisms 010 \to 1 and 101 \to 0 that are mutually inverse
  • nLab Link
  • Related categories: {01}\{0 \to 1\}1\mathbf{1}

This is the 'walking isomorphism' category. The name comes from the fact that it consists of two objects and an isomorphism between them, and a functor out of this category is the same as an isomorphism in the target category. The walking isomorphism is actually equivalent to the trivial category.

Properties

Properties from the database

Deduced properties

  • is small
    Since it is finite, we deduce that it is small.
  • is essentially finite
    Since it is finite, we deduce that it is essentially finite.
  • is essentially small
    Since it is essentially finite, we deduce that it is essentially small.
  • is finitary algebraic
    Since it is trivial, we deduce that it is finitary algebraic.
  • is a Grothendieck topos
    Since it is trivial, we deduce that it is a Grothendieck topos.
  • is split abelian
    Since it is trivial, we deduce that it is split abelian.
  • is self-dual
    Since it is trivial, we deduce that it is self-dual.
  • is essentially discrete
    Since it is trivial, we deduce that it is essentially discrete.
  • is locally finitely presentable
    Since it is finitary algebraic, we deduce that it is locally finitely presentable.
  • is an elementary topos
    Since it is a Grothendieck topos, we deduce that it is an elementary topos.
  • has coproducts
    Since it is a Grothendieck topos, we deduce that it has coproducts.
  • has a generator
    Since it is a Grothendieck topos, we deduce that it has a generator.
  • is locally essentially small
    Since it is a Grothendieck topos, we deduce that it is locally essentially small.
  • is locally presentable
    Since it is a Grothendieck topos, we deduce that it is locally presentable.
  • has a cogenerator
    Since it is a Grothendieck topos, we deduce that it has a cogenerator.
  • is abelian
    Since it is split abelian, we deduce that it is abelian.
  • is Malcev
    Since it is abelian, we deduce that it is Malcev.
  • is inhabited
    Since it has a generator, we deduce that it is inhabited.
  • is finitely complete
    Since it is Malcev, we deduce that it is finitely complete.
  • is thin
    Since it is essentially small and has coproducts, we deduce that it is thin.
  • has connected colimits
    Since it is essentially discrete, we deduce that it has connected colimits.
  • has coequalizers
    Since it is thin, we deduce that it has coequalizers.
  • is right cancellative
    Since it is thin, we deduce that it is right cancellative.
  • is cocomplete
    Since it has coproducts and has coequalizers, we deduce that it is cocomplete.
  • has finite coproducts
    Since it has coproducts, we deduce that it has finite coproducts.
  • has countable coproducts
    Since it has coproducts, we deduce that it has countable coproducts.
  • has an initial object
    Since it has finite coproducts, we deduce that it has an initial object.
  • has binary coproducts
    Since it has finite coproducts, we deduce that it has binary coproducts.
  • has pushouts
    Since it has binary coproducts and has coequalizers, we deduce that it has pushouts.
  • is connected
    Since it has an initial object, we deduce that it is connected.
  • has wide pushouts
    Since it has connected colimits, we deduce that it has wide pushouts.
  • has filtered colimits
    Since it has wide pushouts, we deduce that it has filtered colimits.
  • is Cauchy complete
    Since it has coequalizers, we deduce that it is Cauchy complete.
  • has sequential colimits
    Since it has coequalizers and has countable coproducts, we deduce that it has sequential colimits.
  • is complete
    Since it is essentially small and is thin and is cocomplete, we deduce that it is complete.
  • is finitely cocomplete
    Since it is self-dual and is finitely complete, we deduce that it is finitely cocomplete.
  • has a terminal object
    Since it is self-dual and has an initial object, we deduce that it has a terminal object.
  • has products
    Since it is self-dual and has coproducts, we deduce that it has products.
  • has finite products
    Since it is self-dual and has finite coproducts, we deduce that it has finite products.
  • has binary products
    Since it is self-dual and has binary coproducts, we deduce that it has binary products.
  • has countable products
    Since it is self-dual and has countable coproducts, we deduce that it has countable products.
  • has equalizers
    Since it is self-dual and has coequalizers, we deduce that it has equalizers.
  • has filtered limits
    Since it is self-dual and has filtered colimits, we deduce that it has filtered limits.
  • has sequential limits
    Since it is self-dual and has sequential colimits, we deduce that it has sequential limits.
  • has connected limits
    Since it is self-dual and has connected colimits, we deduce that it has connected limits.
  • has pullbacks
    Since it is self-dual and has pushouts, we deduce that it has pullbacks.
  • is left cancellative
    Since it is self-dual and is right cancellative, we deduce that it is left cancellative.
  • has wide pullbacks
    Since it is self-dual and has wide pushouts, we deduce that it has wide pullbacks.
  • is locally small
    Since it is small, we deduce that it is locally small.
  • is well-powered
    Since it is essentially small, we deduce that it is well-powered.
  • is well-copowered
    Since it is essentially small, we deduce that it is well-copowered.
  • is a groupoid
    Since it is essentially discrete, we deduce that it is a groupoid.
  • has a strict initial object
    Since it is left cancellative and has an initial object, we deduce that it has a strict initial object.
  • has exact filtered colimits
    Since it is locally finitely presentable, we deduce that it has exact filtered colimits.
  • is locally ℵ₁-presentable
    Since it is locally finitely presentable, we deduce that it is locally ℵ₁-presentable.
  • is cartesian closed
    Since it is an elementary topos, we deduce that it is cartesian closed.
  • has a subobject classifier
    Since it is an elementary topos, we deduce that it has a subobject classifier.
  • has disjoint finite coproducts
    Since it is an elementary topos, we deduce that it has disjoint finite coproducts.
  • is epi-regular
    Since it is an elementary topos, we deduce that it is epi-regular.
  • is mono-regular
    Since it has a subobject classifier, we deduce that it is mono-regular.
  • is additive
    Since it is abelian, we deduce that it is additive.
  • is Grothendieck abelian
    Since it is abelian and has coproducts and has a generator and has exact filtered colimits, we deduce that it is Grothendieck abelian.
  • is balanced
    Since it is mono-regular, we deduce that it is balanced.
  • has a strict terminal object
    Since it is right cancellative and has a terminal object, we deduce that it has a strict terminal object.
  • is preadditive
    Since it is additive, we deduce that it is preadditive.
  • has disjoint coproducts
    Since it has coproducts and has disjoint finite coproducts, we deduce that it has disjoint coproducts.
  • is distributive
    Since it is cartesian closed and has finite coproducts, we deduce that it is distributive.
  • is infinitary distributive
    Since it is cartesian closed and has coproducts, we deduce that it is infinitary distributive.
  • has zero morphisms
    Since it is preadditive, we deduce that it has zero morphisms.
  • is pointed
    Since it has zero morphisms and has a terminal object, we deduce that it is pointed.

Non-Properties

Non-Properties from the database

  • is not skeletal
    The two objects are isomorphic, but different.

Deduced Non-Properties*

  • is not discrete
    Assume for a contradiction that it is discrete. Since it is discrete, we deduce that it is skeletal. This is a contradiction since we already know that it is not skeletal.

*This also uses the deduced properties.

Unknown properties

Special morphisms

  • Isomorphisms: every morphism
    trivial
  • Monomorphisms: every morphism
  • Epimorphisms: every morphism
    it is a groupoid