1,855 research outputs found
A note on two notions of compliance
We establish a relation between two models of contracts: binary session
types, and a model based on event structures and game-theoretic notions. In
particular, we show that compliance in session types corresponds to the
existence of certain winning strategies in game-based contracts.Comment: In Proceedings ICE 2014, arXiv:1410.701
A new operational representation of dependencies in Event Structures
The execution of an event in a complex and distributed system where the
dependencies vary during the evolution of the system can be represented in many
ways, and one of them is to use Context-Dependent Event structures. Event
structures are related to Petri nets. The aim of this paper is to propose what
can be the appropriate kind of Petri net corresponding to Context-Dependent
Event structures, giving an operational flavour to the dependencies represented
in a Context/Dependent Event structure. Dependencies are often operationally
represented, in Petri nets, by tokens produced by activities and consumed by
others. Here we shift the perspective using contextual arcs to characterize
what has happened so far and in this way to describe the dependencies among the
various activities
Dependencies and Simultaneity in Membrane Systems
Membrane system computations proceed in a synchronous fashion: at each step
all the applicable rules are actually applied. Hence each step depends on the
previous one. This coarse view can be refined by looking at the dependencies
among rule occurrences, by recording, for an object, which was the a rule that
produced it and subsequently (in a later step), which was the a rule that
consumed it. In this paper we propose a way to look also at the other main
ingredient in membrane system computations, namely the simultaneity in the rule
applications. This is achieved using zero-safe nets that allows to synchronize
transitions, i.e., rule occurrences. Zero-safe nets can be unfolded into
occurrence nets in a classical way, and to this unfolding an event structure
can be associated. The capability of capturing simultaneity of zero-safe nets
is transferred on the level of event structure by adding a way to express which
events occur simultaneously
A new operational representation of dependencies in Event Structures
The execution of an event in a complex and distributed system where the
dependencies vary during the evolution of the system can be represented in many
ways, and one of them is to use Context-Dependent Event structures. Event
structures are related to Petri nets. The aim of this paper is to propose what
can be the appropriate kind of Petri net corresponding to Context-Dependent
Event structures, giving an operational flavour to the dependencies represented
in a Context/Dependent Event structure. Dependencies are often operationally
represented, in Petri nets, by tokens produced by activities and consumed by
others. Here we shift the perspective using contextual arcs to characterize
what has happened so far and in this way to describe the dependencies among the
various activities
Representing Dependencies in Event Structures
Event structures where the causality may explicitly change during a
computation have recently gained the stage. In this kind of event structures
the changes in the set of the causes of an event are triggered by modifiers
that may add or remove dependencies, thus making the happening of an event
contextual. Still the focus is always on the dependencies of the event. In this
paper we promote the idea that the context determined by the modifiers plays a
major role, and the context itself determines not only the causes but also what
causality should be. Modifiers are then used to understand when an event (or a
set of events) can be added to a configuration, together with a set of events
modeling dependencies, which will play a less important role. We show that most
of the notions of Event Structure presented in literature can be translated
into this new kind of event structure, preserving the main notion, namely the
one of configuration
A Petri net view of covalent bonds
In nature and chemistry the interactions among elements often form bonds and among them covalent bonds are relevant, involving the sharing of electrons. Another relevant and compelling facet of calculi modelling covalent bonds is that certain steps in reactions are the result of concerting different activities, possibly reversing some of them. Starting from a calculus for covalent bonds, we investigate on how it can be done in a compositional fashion and how it can be encoded in suitable Petri nets. The outcome gives us a compositional covalent bond calculus and a truly distributed implementation. On these results it is possible to build a behavioural equivalence among terms.Fil: Melgratti, Hernan Claudio. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; ArgentinaFil: Mezzina, Claudio Antares. Università Degli Studi Di Urbino Carlo Bo; ItaliaFil: Pinna, G. Michele. Università degli Studi di Cagliari; Itali
A Truly Concurrent Semantics for Reversible CCS
Reversible CCS (RCCS) is a well-established, formal model for reversible
communicating systems, which has been built on top of the classical Calculus of
Communicating Systems (CCS). In its original formulation, each CCS process is
equipped with a memory that records its performed actions, which is then used
to reverse computations. More recently, abstract models for RCCS have been
proposed in the literature, basically, by directly associating RCCS processes
with (reversible versions of) event structures. In this paper we propose a
different abstract model: starting from one of the well-known encoding of CCS
into Petri nets we apply a recently proposed approach to incorporate
causally-consistent reversibility to Petri nets, obtaining as result the
(reversible) net counterpart of every RCCS term
- …