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A Coalgebraic Semantics of Subtyping

Erik Poll (2010)

RAIRO - Theoretical Informatics and Applications

Coalgebras have been proposed as formal basis for the semantics of objects in the sense of object-oriented programming. This paper shows that this semantics provides a smooth interpretation for subtyping, a central notion in object-oriented programming. We show that different characterisations of behavioural subtyping found in the literature can conveniently be expressed in coalgebraic terms. We also investigate the subtle difference between behavioural subtyping and refinement.

A coalgebraic semantics of subtyping

Erik Poll (2001)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

Coalgebras have been proposed as formal basis for the semantics of objects in the sense of object-oriented programming. This paper shows that this semantics provides a smooth interpretation for subtyping, a central notion in object-oriented programming. We show that different characterisations of behavioural subtyping found in the literature can conveniently be expressed in coalgebraic terms. We also investigate the subtle difference between behavioural subtyping and refinement.

A generalization of traces

Walter Vogler (1991)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

A hybrid evolutionary approach to intelligent system design.

Amr Badr, Ibrahim Farag, Saad Eid (1999)

Mathware and Soft Computing

The problem of developing a general methodology for system design has always been demanding. For this purpose, an evolutionary algorithm, adapted with design-specific representation data structures is devised. The representation modeling the system to be designed, is composed of three levels of abstraction: the first, is an 'abstract brain' layer - mainly a number of competing finite state machines, which in turn control the second level composed of fuzzy Petri nets; the third level constitutes...

A Note on Negative Tagging for Least Fixed-Point Formulae

Dilian Gurov, Bruce Kapron (2010)

RAIRO - Theoretical Informatics and Applications

Proof systems with sequents of the form U ⊢ Φ for proving validity of a propositional modal μ-calculus formula Φ over a set U of states in a given model usually handle fixed-point formulae through unfolding, thus allowing such formulae to reappear in a proof. Tagging is a technique originated by Winskel for annotating fixed-point formulae with information about the proof states at which these are unfolded. This information is used later in the proof to avoid unnecessary unfolding, without...

A novel continuous model to approximate time Petri nets: modelling and analysis

Tianlong Gu, Rongsheng Dong (2005)

International Journal of Applied Mathematics and Computer Science

In order to approximate discrete-event systems in which there exist considerable states and events, David and Alla define a continuous Petri net (CPN). So far, CPNs have been a useful tool not only for approximating discrete-event systems but also for modelling continuous processes. Due to different ways of calculating instantaneous firing speeds of transitions, various continuous Petri net models, such as the CCPN (constant speed CPN), VCPN (variable speed CPN) and the ACPN (asymptotic CPN), have...

An application of the theory of intuitionistic fuzzy multigraphs.

Krassimir Atanassov, B. K. Papadopoulos, A. Syropoulos (2004)

Mathware and Soft Computing

In a recent paper by one of the authors it has been shown that there is a relationship between algebraic structures and labeled transition systems. Indeed, it has been shown that an algebraic structures can be viewed as labeled transition systems, which can also be viewed as multigraphs. In this paper, we extend this work by providing an estimation of the transition possibilities between vertices that are connected with multiarcs.

Analyzing the dynamics of deterministic systems from a hypergraph theoretical point of view

Luis M. Torres, Annegret K. Wagler (2013)

RAIRO - Operations Research - Recherche Opérationnelle

To model the dynamics of discrete deterministic systems, we extend the Petri nets framework by a priority relation between conflicting transitions, which is encoded by orienting the edges of a transition conflict graph. The aim of this paper is to gain some insight into the structure of this conflict graph and to characterize a class of suitable orientations by an analysis in the context of hypergraph theory.

Bisimulation on speed: Lower time bounds

Gerald Lüttgen, Walter Vogler (2010)

RAIRO - Theoretical Informatics and Applications

More than a decade ago, Moller and Tofts published their seminal work on relating processes, which are annotated with lower time bounds, with respect to speed. Their paper has left open many questions regarding the semantic theory for the suggested bisimulation-based faster-than preorder, the MT-preorder, which have not been addressed since. The encountered difficulties concern a general compositionality result, a complete axiom system for finite processes, a convincing intuitive justification...

Bisimulation on speed : lower time bounds

Gerald Lüttgen, Walter Vogler (2005)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

More than a decade ago, Moller and Tofts published their seminal work on relating processes, which are annotated with lower time bounds, with respect to speed. Their paper has left open many questions regarding the semantic theory for the suggested bisimulation-based faster-than preorder, the MT-preorder, which have not been addressed since. The encountered difficulties concern a general compositionality result, a complete axiom system for finite processes, a convincing intuitive justification of...

Calculi of net structures and sets are similar

Ludwik Czaja (2007)

RAIRO - Theoretical Informatics and Applications

Three basic operations on labelled net structures are proposed: synchronised union, synchronised intersection and synchronised difference. The first of them is a version of known parallel composition with synchronised actions identically labelled. The operations work analogously to the ordinary union, intersection and difference on sets. It is shown that the universe of net structures with these operations is a distributive lattice and – if infinite pre/post sets of transitions are allowed – even...

Calculi of net structures and sets are similar

Ludwik Czaja (2008)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

Three basic operations on labelled net structures are proposed: synchronised union, synchronised intersection and synchronised difference. The first of them is a version of known parallel composition with synchronised actions identically labelled. The operations work analogously to the ordinary union, intersection and difference on sets. It is shown that the universe of net structures with these operations is a distributive lattice and – if infinite pre/post sets of transitions are allowed – even...

Colored decision process Petri nets: modeling, analysis and stability

Julio Clempner (2005)

International Journal of Applied Mathematics and Computer Science

In this paper we introduce a new modeling paradigm for developing a decision process representation called the Colored Decision Process Petri Net (CDPPN). It extends the Colored Petri Net (CPN) theoretic approach including Markov decision processes. CPNs are used for process representation taking advantage of the formal semantic and the graphical display. A Markov decision process is utilized as a tool for trajectory planning via a utility function. The main point of the CDPPN is its ability to...

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