Abstract
Let us recall the definition of a comma category (mid level of generalization). If \( G:\mathcal{D}\Rightarrow \mathcal{C} \) is a functor and \( C\in \mathcal{C} \) is an (anchor) object, then the comma category (C → G) is the category whose objects are the pairs
for \( U\in \mathcal{D} \). Moreover, a morphism
between comma objects is essentially just a morphism τ: U → D in \( \mathcal{D} \) for which
(We have dropped the overbar notation \( \overline{\tau} \).)
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Author information
Authors and Affiliations
Rights and permissions
Copyright information
© 2017 The Author(s)
About this chapter
Cite this chapter
Roman, S. (2017). Universality. In: An Introduction to the Language of Category Theory. Compact Textbooks in Mathematics. Birkhäuser, Cham. https://doi.org/10.1007/978-3-319-41917-6_3
Download citation
DOI: https://doi.org/10.1007/978-3-319-41917-6_3
Published:
Publisher Name: Birkhäuser, Cham
Print ISBN: 978-3-319-41916-9
Online ISBN: 978-3-319-41917-6
eBook Packages: Mathematics and StatisticsMathematics and Statistics (R0)