nLab
identifier
Contents
Context
2-Category theory
2-category theory
Definitions
Transfors between 2-categories
Morphisms in 2-categories
Structures in 2-categories
Limits in 2-categories
Structures on 2-categories
Limits and colimits
limits and colimits
1-Categorical
limit and colimit
limits and colimits by example
commutativity of limits and colimits
small limit
filtered colimit
sifted colimit
connected limit , wide pullback
preserved limit , reflected limit , created limit
product , fiber product , base change , coproduct , pullback , pushout , cobase change , equalizer , coequalizer , join , meet , terminal object , initial object , direct product , direct sum
finite limit
Kan extension
weighted limit
end and coend
fibered limit
2-Categorical
(∞,1)-Categorical
Model-categorical
Contents
Idea
An identifier is a particular kind of conical 2-limit in a 2-category , which universally renders a 2-cell between a parallel pair of 1-cells the equality 2-arrow. Its diagram shape is a single 2-arrow α : f ⇒ g \alpha\colon f \Rightarrow g f , g : X → Y f,g\colon X\to Y
Related pages
Last revised on September 19, 2026 at 08:43:33.
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