category of sets
- notation:
- objects: sets
- morphisms: maps
- Related categories: , ,
- nLab Link
- Dual category:
The category of sets plays a fundamental role in category theory. Due to the Yoneda embedding, many results about general categories can be reduced to the category of sets. It is also usually the first example of a category that one encounters.
Satisfied Properties
Properties from the database
Deduced properties
- is locally essentially small
- has a generator
- has a generating set
- is inhabited
- is locally strongly finitely presentable
- is well-copowered
- is regular
- is finitely complete
- has equalizers
- has coreflexive equalizers
- has finite products
- has binary products
- has a terminal object
- has pullbacks
- is Cauchy complete
- has finite powers
- has binary powers
- is connected
- has a multi-terminal object
- is locally finitely presentable
- is locally ℵ₁-presentable
- is locally presentable
- has exact filtered colimits
- has filtered colimits
- has directed colimits
- has cartesian filtered colimits
- is cocomplete
- is finitely accessible
- is ℵ₁-accessible
- is accessible
- is well-powered
- is a generalized variety
- has sifted colimits
- has reflexive coequalizers
- is multi-algebraic
- is locally finitely multi-presentable
- has connected limits
- has wide pullbacks
- is complete
- has products
- has countable products
- has powers
- has countable powers
- has cofiltered limits
- has sequential limits
- is multi-complete
- is locally multi-presentable
- is multi-cocomplete
- is locally poly-presentable
- has coproducts
- is an elementary topos
- is cartesian closed
- is infinitary distributive
- is countably distributive
- has countable coproducts
- is distributive
- has finite coproducts
- has a strict initial object
- has an initial object
- has a subobject classifier
- is mono-regular
- is balanced
- has a regular subobject classifier
- has disjoint finite coproducts
- has disjoint coproducts
- is epi-regular
- is finitely cocomplete
- has a cogenerator
- is infinitary extensive
- is extensive
- has cocartesian cofiltered limits
- is locally cartesian closed
- is coregular
- is co-Malcev
- has a natural numbers object
- is filtered
- is sifted
- has connected colimits
- has cosifted limits
- has copowers
- has binary coproducts
- has coequalizers
- has countable copowers
- has sequential colimits
- has pushouts
- has directed limits
- has wide pushouts
- has finite copowers
- has binary copowers
- has a multi-initial object
- has a cogenerating set
- is cosifted
- is cofiltered
Unsatisfied Properties
Properties from the database
Deduced properties*
- is not direct
- is not discrete
- is not thin
- does not have a strict terminal object
- is not right cancellative
- is not left cancellative
- is not a groupoid
- is not one-way
- is not essentially discrete
- is not trivial
- is not pointed
- does not have zero morphisms
- does not have kernels
- does not have biproducts
- is not normal
- is not preadditive
- is not additive
- is not abelian
- is not Grothendieck abelian
- is not split abelian
- is not essentially small
- is not small
- is not essentially countable
- is not essentially finite
- is not finite
- is not countable
- is not locally copresentable
- is not strongly connected
- is not unital
- does not have cokernels
- does not have disjoint finite products
- does not have disjoint products
- is not codistributive
- is not countably codistributive
- is not infinitary codistributive
- is not cocartesian coclosed
- is not coextensive
- is not infinitary coextensive
- is not conormal
- is not inverse
- is not coaccessible
- does not have a regular quotient object classifier
- does not have a quotient object classifier
- is not locally cocartesian coclosed
- is not counital
- is not self-dual
*This also uses the deduced satisfied properties.
Unknown properties
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Special objects
- terminal object: singleton set
- initial object: empty set
- products: direct products with pointwise operations
- coproducts: disjoint union
Special morphisms
- isomorphisms: bijective maps
- monomorphisms: injective maps
- epimorphisms: surjective maps
- regular monomorphisms: same as monomorphisms
- regular epimorphisms: surjective homomorphisms