BIB-VERSION:: CS-TR-v2.0
          ID:: SBCS//stark/fibrations1.ps.gz
       ENTRY:: June 4, 1998
ORGANIZATION:: State University of New York at Stony Brook, Computer Science
       TITLE:: {Fibrational Semantics of Dataflow Networks
        TYPE:: Preprint
      AUTHOR:: Stark, Eugene W.
     CONTACT:: Eugene W. Stark, Department of Computer Science,
                   SUNY at Stony Brook, Stony Brook, NY 11794-4400
                   Tel: 516-632-8444 <stark@cs.sunysb.edu>
        DATE:: June, 1998
   RETRIEVAL:: HTTP from BSD7.CS.SUNYSB.EDU with the URL
		   http://bsd7.cs.sunysb.edu/~stark/REPORTS/fibrations1.ps.gz

ABSTRACT::

Beginning with the category Dom of Scott domains and continuous maps,
we introduce a syntax for dataflow networks as ``systems of inequalities,''
and provide an associated operational semantics.
We observe that, under this semantics, a system of inequalities determines
a two-sided fibration in Dom.  This leads to the introduction of a
certain class of cartesian arrows of spans as a notion of morphism
for systems.  The resulting structure Sys, consisting of domains,
systems, and morphisms, forms a bicategory that embeds Dom up to
equivalence and is suitable as a semantic model for nondeterministic
networks.  Isomorphism in Sys amounts to a notion of system
equivalence ``up to deterministic internal computations.''