In “Arbib, Manes. Arrows, Structures and Functors. The Categorical Imperative. 6. Structured sets.” there is an approach to formalize structures. I have a strong feeling that they describe just concrete categories in other words. For a concrete category $(C, U)$, the set of structures on a set $X$ (this is Arbib, Manes's term) is $(fr\\_ob(U))^{-1}(X)$ where $fr\\_ob(U)$ is a mapping of $U$ on objects. Similarly, the set of admissible functions $A\to B$ (for $A\ B\in ob(C)$) is $im(fr\\_hom(U)(A, B))$ where $fr\\_hom(U)$ is a mapping of $U$ on morphisms.

If I am on the right track, what do other parts of Arbib, Manes's theory (e.g. optimal lifts) correspond to?

(Please add the tag “concrete-category” to this question.)

  • 1
    $\begingroup$ The "ct.x" style tags are reserved for arXiv subjects. $\endgroup$ Sep 13, 2011 at 16:18
  • $\begingroup$ @Qiaochu Yuan: Thanks, I did not know that. I have removed “ct.”. $\endgroup$
    – beroal
    Sep 16, 2011 at 18:18


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy