27 research outputs found
Between quantum logic and concurrency
We start from two closure operators defined on the elements of a special kind
of partially ordered sets, called causal nets. Causal nets are used to model
histories of concurrent processes, recording occurrences of local states and of
events. If every maximal chain (line) of such a partially ordered set meets
every maximal antichain (cut), then the two closure operators coincide, and
generate a complete orthomodular lattice. In this paper we recall that, for any
closed set in this lattice, every line meets either it or its orthocomplement
in the lattice, and show that to any line, a two-valued state on the lattice
can be associated. Starting from this result, we delineate a logical language
whose formulas are interpreted over closed sets of a causal net, where every
line induces an assignment of truth values to formulas. The resulting logic is
non-classical; we show that maximal antichains in a causal net are associated
to Boolean (hence "classical") substructures of the overall quantum logic.Comment: In Proceedings QPL 2012, arXiv:1407.842
Soundness-preserving composition of synchronously and asynchronously interacting workflow net components
In this paper, we propose a compositional approach to construct formal models
of complex distributed systems with several synchronously and asynchronously
interacting components. A system model is obtained from a composition of
individual component models according to requirements on their interaction. We
represent component behavior using workflow nets - a class of Petri nets. We
propose a general approach to model and compose synchronously and
asynchronously interacting workflow nets. Through the use of Petri net
morphisms and their properties, we prove that this composition of workflow nets
preserves component correctness.Comment: Preprint of the paper submitted to "Fundamenta Informaticae
Application and Theory of Petri Nets33rd International Conference, PETRI NETS 2012, Hamburg, Germany, June 25-29, 2012. Proceedings /
XI, 419p.online resource
Non-Interference Notions Based on Reveals and Excludes Relations for Petri Nets
Abstract. In distributed systems, it is often important that a user is not able to infer if a given action has been performed by another component, while still being able to interact with that component. This kind of problems has been studied with the help of a notion of "interference" in formal models of concurrent systems (e.g. CCS, Petri nets). Here, we propose several new notions of interference for ordinary Petri nets, study some of their properties, and compare them with notions already proposed in the literature. Our new notions rely on the unfolding of Petri nets, and on an adaptation of the "reveals" relation for ordinary Petri nets, previously defined on occurrence nets, and on a new relation, called "excludes", here introduced for detecting negative information flow
Between quantum logic and concurrency
We start from two closure operators defined on the elements of
a special kind of partially ordered sets. These are called
causal nets, and are used to model histories of concurrent
processes, recording occurrences of local states and of events.
If every maximal chain (line) of the partially ordered set meets
every maximal antichain (cut), then the two closure operators coincide,
and generate complete orthomodular lattices. In this paper we
recall that, for any closed set in this lattice, every line meets
either it or its orthocomplement in the lattice, and show that
to any line, a two-valued state on the lattice can be associated.
Starting from this result, we delineate a logical language whose
formulas are interpreted over closed sets of a causal net, where
every line induces an assignment of truth values to formulas.
The resulting logic is non-classical; we show that maximal
antichains in a causal net are associated to Boolean (hence
``classical'') substructures of the overall quantum logic.JRC.G.5-Security technology assessmen