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A Relational Model of NonDeterministic Dataflow
 In CONCUR'98, volume 1466 of LNCS
, 1998
"... . We recast dataflow in a modern categorical light using profunctors as a generalisation of relations. The well known causal anomalies associated with relational semantics of indeterminate dataflow are avoided, but still we preserve much of the intuitions of a relational model. The development fits ..."
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Cited by 28 (13 self)
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. We recast dataflow in a modern categorical light using profunctors as a generalisation of relations. The well known causal anomalies associated with relational semantics of indeterminate dataflow are avoided, but still we preserve much of the intuitions of a relational model. The development fits with the view of categories of models for concurrency and the general treatment of bisimulation they provide. In particular it fits with the recent categorical formulation of feedback using traced monoidal categories. The payoffs are: (1) explicit relations to existing models and semantics, especially the usual axioms of monotone IO automata are read off from the definition of profunctors, (2) a new definition of bisimulation for dataflow, the proof of the congruence of which benefits from the preservation properties associated with open maps and (3) a treatment of higherorder dataflow as a biproduct, essentially by following the geometry of interaction programme. 1 Introduction A fundament...
Arithmetic + Logic + Geometry = Concurrency
 In Proc. First Latin American Symposium on Theoretical Informatics, LNCS 583
, 1992
"... This paper ties together three primitivist views of concurrency whose development the author has had some involvement with, namely the arithmetic of schedules, the logic of scheduleautomaton duality, and the geometry of automata. Separately each of these views shed considerable light on concurrency ..."
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Cited by 7 (3 self)
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This paper ties together three primitivist views of concurrency whose development the author has had some involvement with, namely the arithmetic of schedules, the logic of scheduleautomaton duality, and the geometry of automata. Separately each of these views shed considerable light on concurrency. Our goal here is to bring these three views together coherently in the one place. The general picture is as follows. 1 2 3 Arithmetic of Schedules
Towards a Complete Hierarchy of Compositional Dataflow Models
 IN: PROC. THEORETICAL ASPECTS OF COMPUTER SOFTWARE, LNCS 526
, 1991
"... A dataflow network consists of nodes that communicate by passing data over unbounded FIFO channels. For dataflow networks containing only deterministic nodes, Kahn has presented a simple and elegant semantic model. However, the generalization of this model is not compositional for nondeterministi ..."
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Cited by 5 (0 self)
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A dataflow network consists of nodes that communicate by passing data over unbounded FIFO channels. For dataflow networks containing only deterministic nodes, Kahn has presented a simple and elegant semantic model. However, the generalization of this model is not compositional for nondeterministic networks. Past work has
A Kahn principle for networks of nonmonotonic realtime processes
, 1992
"... We show that the inputoutput function computed by a network of asynchronous realtime processes is denoted by the unique fixed point of a Scott continuous functional even though the network or its components may compute a discontinuous function. This extends a wellknown principle of Kahn [Kahn, 1 ..."
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Cited by 5 (1 self)
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We show that the inputoutput function computed by a network of asynchronous realtime processes is denoted by the unique fixed point of a Scott continuous functional even though the network or its components may compute a discontinuous function. This extends a wellknown principle of Kahn [Kahn, 1974] to an important class of parallel systems that has resisted the traditional fixed point approach. We present a fully abstract ordertheoretic denotational semantics for networks of asynchronous realtime processes. The timesensitive nature of the component processes allows them to compute functions which are not Scott continuous, nor even monotonic, on the domain of timed message streams ordered by the usual prefix relation. Because of the discontinuous behavior of the components, the characterization of networks with nonmonotonic processes as fixed points of continuous functionals (the standard approach of denotational semantics, applied to untimed networks of monotonic processes by K...
Connectedness and Synchronization
 In Images of Programming. North Holland Publ. Co
, 1991
"... this paper we supplement the taxonomy list above with another kind of semantical domains, namely we consider connected relations. In the most general setting connected relations are parametrized by a given domain D which obeys some specific finiteness conditions; we say that D is an Fdomain [RT3]. ..."
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Cited by 3 (3 self)
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this paper we supplement the taxonomy list above with another kind of semantical domains, namely we consider connected relations. In the most general setting connected relations are parametrized by a given domain D which obeys some specific finiteness conditions; we say that D is an Fdomain [RT3]. In the particular case when D is the domain of natural numbers, connected relations appeared first in [Maz1] under the name of multitrees. For connected relations one can define a natural version of synchronization (strong conjunction).