Hostname: page-component-8448b6f56d-42gr6 Total loading time: 0 Render date: 2024-04-24T20:00:58.230Z Has data issue: false hasContentIssue false

Universal homogeneous graph-like structures and domains

Published online by Cambridge University Press:  26 February 2002

PAOLO BOLDI
Affiliation:
Università degli Studi di Milano, Dip. di Scienze dell’Informazione Via Comelico 39/41, I-20135 Milano. e-mail: boldi@dsi.unimi.it
FELICE CARDONE
Affiliation:
Università di Milano Bicocca, Dip. di Informatica, Sistemistica e Comunicazione (DISCo) Via Bicocca degli Arcimboldi 8, I-20126 Milano. e-mail: cardone@disco.unimib.it
MANFRED DROSTE
Affiliation:
Technische Universität Dresden, Institut für Algebra, D-01062 Dresden. e-mail: droste@math.tu-dresden.de

Abstract

We present explicit constructions of universal homogeneous objects in categories of domains with stable embedding–projection pairs as arrows. These results make use of a representation of such domains through graph-like structures and apply a generalization of Rado’s result on the existence of the universal homogeneous countable graph. In particular, we build universal homogeneous objects in the categories of coherence spaces and qualitative domains, introduced by Girard (Girard 1987; Girard 1986), and two categories of hypercoherences recently studied by Ehrhard (Ehrhard 1993). Our constructions rely on basic numerical notions. We also show that a suitable random construction of Rado’s graph and its generalizations produces with probability 1 the universal homogeneous structures presented here.

Type
Research Article
Copyright
2002 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)