2019/10/19 by Josep Elgueta, Elgueta, Josep · 1 citation
Computer Science · Mathematics · Decision Sciences · #semigroups and automata theory #Rings, Modules, and Algebras #Fuzzy and Soft Set Theory
paper · pdf · doi:10.48550/arxiv.1910.08757
Let \widehat\mathbbF\mathbbSet be the groupoid of finite sets and bijections between them equipped with the canonical symmetric rig category structure given by the disjoint union and the cartesian product of finite sets. We prove that the category (in fact, groupoid) of endomorphisms of \widehat\mathbbF\mathbbSet is equivalent to the terminal category, thus providing some evidence that \widehat\mathbbF\mathbbSet is the right categorical analog of the commutative rig ℕ of nonnegative integers. This is shown using a particular semistrict skeletal version of \widehat\mathbbF\mathbbSet for which the endomorphisms can be described very explicitly.