3,464 research outputs found
Primitives for Contract-based Synchronization
We investigate how contracts can be used to regulate the interaction between
processes. To do that, we study a variant of the concurrent constraints
calculus presented in [1], featuring primitives for multi-party synchronization
via contracts. We proceed in two directions. First, we exploit our primitives
to model some contract-based interactions. Then, we discuss how several models
for concurrency can be expressed through our primitives. In particular, we
encode the pi-calculus and graph rewriting.Comment: In Proceedings ICE 2010, arXiv:1010.530
Mapping Fusion and Synchronized Hyperedge Replacement into Logic Programming
In this paper we compare three different formalisms that can be used in the
area of models for distributed, concurrent and mobile systems. In particular we
analyze the relationships between a process calculus, the Fusion Calculus,
graph transformations in the Synchronized Hyperedge Replacement with Hoare
synchronization (HSHR) approach and logic programming. We present a translation
from Fusion Calculus into HSHR (whereas Fusion Calculus uses Milner
synchronization) and prove a correspondence between the reduction semantics of
Fusion Calculus and HSHR transitions. We also present a mapping from HSHR into
a transactional version of logic programming and prove that there is a full
correspondence between the two formalisms. The resulting mapping from Fusion
Calculus to logic programming is interesting since it shows the tight analogies
between the two formalisms, in particular for handling name generation and
mobility. The intermediate step in terms of HSHR is convenient since graph
transformations allow for multiple, remote synchronizations, as required by
Fusion Calculus semantics.Comment: 44 pages, 8 figures, to appear in a special issue of Theory and
Practice of Logic Programming, minor revisio
An Algebra of Hierarchical Graphs
We define an algebraic theory of hierarchical graphs, whose axioms characterise graph isomorphism: two terms are equated exactly when they represent the same graph. Our algebra can be understood as a high-level language for describing graphs with a node-sharing, embedding structure, and it is then well suited for defining graphical representations of software models where nesting and linking are key aspects
An Algebra of Hierarchical Graphs and its Application to Structural Encoding
We define an algebraic theory of hierarchical graphs, whose axioms
characterise graph isomorphism: two terms are equated exactly when
they represent the same graph. Our algebra can be understood as
a high-level language for describing graphs with a node-sharing, embedding
structure, and it is then well suited for defining graphical
representations of software models where nesting and linking are key
aspects. In particular, we propose the use of our graph formalism as a
convenient way to describe configurations in process calculi equipped
with inherently hierarchical features such as sessions, locations, transactions,
membranes or ambients. The graph syntax can be seen as an
intermediate representation language, that facilitates the encodings of
algebraic specifications, since it provides primitives for nesting, name
restriction and parallel composition. In addition, proving soundness
and correctness of an encoding (i.e. proving that structurally equivalent
processes are mapped to isomorphic graphs) becomes easier as it can
be done by induction over the graph syntax
Chemical concrete machine
The chemical concrete machine is a graph rewriting system which uses only
local moves (rewrites), seen as chemical reactions involving molecules which
are graphs made up by 4 trivalent nodes. It is Turing complete, therefore it
might be used as a model of computation in algorithmic chemistry
Deriving Bisimulation Congruences using 2-Categories
We introduce G-relative-pushouts (GRPO) which are a 2-categorical generalisation of relative-pushouts (RPO). They are suitable for deriving labelled transition systems (LTS) for process calculi where terms are viewed modulo structural congruence. We develop their basic properties and show that bisimulation on the LTS derived via GRPOs is a congruence, provided that sufficiently many GRPOs exist. The theory is applied to a simple subset of CCS and the resulting LTS is compared to one derived using a procedure proposed by Sewell
COSMICAH 2005: workshop on verification of COncurrent Systems with dynaMIC Allocated Heaps (a Satellite event of ICALP 2005) - Informal Proceedings
Lisboa Portugal, 10 July 200
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