Quantitative Domains, Groupoids and Linear Logic

We introduce the notion of a candidate for “multiple valued universal constructions” and define stable functors (which generalise functors with left adjoints) in terms of factorisation through candidates. There are many mathematical examples, including the Zariski spectrum of a ring (as shown by Diers [81]) and the Galois group of a polynomial, but we are mainly interested in Berry's [78] minimum data property. In fact we begin with a completely non-mathematical example.