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Unfolding and Event Structure Semantics for Graph Grammars
 PROCEEDINGS OF THE 5TH INTERNATIONAL WORKSHOP ON GRAPH GRAMMARS AND THEIR APPLICATION TO COMPUTER SCIENCE, VOLUME 1073 OF LNCS
, 1996
"... We propose an unfolding semantics for graph transformation systems in the doublepushout (DPO) approach. Mimicking Winskel’s construction for Petri nets, a graph grammar is unfolded into an acyclic branching structure, that is itself a (nondeterministic occurrence) graph grammar describing all the ..."
Abstract

Cited by 33 (21 self)
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We propose an unfolding semantics for graph transformation systems in the doublepushout (DPO) approach. Mimicking Winskel’s construction for Petri nets, a graph grammar is unfolded into an acyclic branching structure, that is itself a (nondeterministic occurrence) graph grammar describing all the possible computations of the original grammar. The unfolding can be abstracted naturally to a prime algebraic domain and then to an event structure semantics. We show that such event structure coincides both with the one defined by Corradini et al. [3] via a
Contextual petri nets, asymmetric event structures and processes
 Information and Computation
, 2001
"... We present an event structure semantics for contextual nets, an extension of P/T Petri nets where transitions can check for the presence of tokens without consuming them (readonly operations). A basic rôle is played by asymmetric event structures, a generalization of Winskel’s prime event structure ..."
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Cited by 32 (13 self)
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We present an event structure semantics for contextual nets, an extension of P/T Petri nets where transitions can check for the presence of tokens without consuming them (readonly operations). A basic rôle is played by asymmetric event structures, a generalization of Winskel’s prime event structures where symmetric conflict is replaced by a relation modelling asymmetric conflict or weak causality, used to represent a new kind of dependency between events arising in contextual nets. Extending Winskel’s seminal work on safe nets, the truly concurrent event based semantics of contextual nets is given at categorical level via a chain of coreflections
An Inductive View of Graph Transformation
 In Workshop on Algebraic Development Techniques
, 1998
"... . The dynamic behavior of rulebased systems (like term rewriting systems [24], process algebras [27], and so on) can be traditionally determined in two orthogonal ways. Either operationally, in the sense that a way of embedding a rule into a state is devised, stating explicitly how the result i ..."
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Cited by 30 (12 self)
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. The dynamic behavior of rulebased systems (like term rewriting systems [24], process algebras [27], and so on) can be traditionally determined in two orthogonal ways. Either operationally, in the sense that a way of embedding a rule into a state is devised, stating explicitly how the result is built: This is the role played by (the application of) a substitution in term rewriting. Or inductively, showing how to build the class of all possible reductions from a set of basic ones: For term rewriting, this is the usual definition of the rewrite relation as the minimal closure of the rewrite rules. As far as graph transformation is concerned, the operational view is by far more popular: In this paper we lay the basis for the orthogonal view. We first provide an inductive description for graphs as arrows of a freely generated dgsmonoidal category. We then apply 2categorical techniques, already known for term and term graph rewriting [29, 7], recasting in this framework the...
Horizontal and Vertical Structuring of Typed Graph Transformation Systems
, 1996
"... this paper we concentrate on structuring and refinement concepts for graph transformation systems. Conceptually, we distinguish between two kinds of structuring. We speak of horizontal structuring if a large specification is obtained by combining and modifying smaller ones, possibly sharing some com ..."
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Cited by 27 (14 self)
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this paper we concentrate on structuring and refinement concepts for graph transformation systems. Conceptually, we distinguish between two kinds of structuring. We speak of horizontal structuring if a large specification is obtained by combining and modifying smaller ones, possibly sharing some common parts. Instead, if we consider the relationship between a more abstract and a more concrete version of the same specification, or between a specification and its implementation, we speak of vertical structuring.
Adhesive highlevel replacement categories and systems
, 2004
"... Adhesive highlevel replacement (HLR) categories and systems are introduced as a new categorical framework for graph transformation in a broad sense, which combines the wellknown concept of HLR systems with the new concept of adhesive categories introduced by Lack and Sobociński. In this paper we s ..."
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Cited by 25 (6 self)
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Adhesive highlevel replacement (HLR) categories and systems are introduced as a new categorical framework for graph transformation in a broad sense, which combines the wellknown concept of HLR systems with the new concept of adhesive categories introduced by Lack and Sobociński. In this paper we show that most of the HLR properties, which had been introduced ad hoc to generalize some basic results from the category of graphs to highlevel structures, are valid already in adhesive HLR categories. As a main new result in a categorical framework we show the Critical Pair Lemma for local confluence of transformations. Moreover we present a new version of embeddings and extensions for transformations in our framework of adhesive HLR systems.
Verifying finitestate graph grammars: an unfoldingbased approach
 IN PROC. OF CONCUR ’04
, 2004
"... ..."
A Generic Graphical Editor for Visual Languages based on Algebraic Graph Grammars
, 1998
"... GENGED is a generic graphical editor supporting the graphical definition of visual languages. Given an alphabet and rules of a specific visual language GENGED generates a syntaxdirected graphical editor for this language. GENGED as well as each visual language defined using GENGED is based on algeb ..."
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Cited by 23 (3 self)
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GENGED is a generic graphical editor supporting the graphical definition of visual languages. Given an alphabet and rules of a specific visual language GENGED generates a syntaxdirected graphical editor for this language. GENGED as well as each visual language defined using GENGED is based on algebraic graph grammars. A sentence is given by a graphical structure consisting of a logical (abstract syntax) and a visual level (concrete syntax). Both levels are connected by layout operations. Visual language rules are defined by graph grammar rules. The underlying logical structure, however, is hidden from the user, but it is essential for a formal presentation and manipulation of graphical structures on both levels. The manipulations are performed by a graph transformation machine working on the logical level, whereas a graphical constraint solver manages the layout the user works with. Keywords: graphical definition of VLs; generation of syntaxdirected graphical editors; visual specifi...
A Combined Reference Model and ViewBased Approach to System Specification
, 1997
"... this paper we present a specification technique based on graph transformations which supports such a development approach. The use of graphs and graph transformations supports an intuitive understanding and an integration of static and dynamic aspects on a welldefined semantical base. On this backg ..."
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Cited by 23 (11 self)
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this paper we present a specification technique based on graph transformations which supports such a development approach. The use of graphs and graph transformations supports an intuitive understanding and an integration of static and dynamic aspects on a welldefined semantical base. On this background, formal notions of view and view relation are developed and the behaviour of views is described by a loose semantics. The integration of two views derived from a common reference model is done in two steps. First, dependencies between the views which are not given by the reference model are determined, and the reference model is extended appropriately. This is the task of a model manager. If the two views and the reference model are consistent, the actual view integration can be performed automatically. For the case of more than two views more general scenarios are developed and discussed. All concepts and results are illustrated at the wellknown example of a banking system.
A BiCategorical Axiomatisation of Concurrent Graph Rewriting
, 1999
"... In this paper the concurrent semantics of doublepushout (DPO) graph rewriting, which is classically defined in terms of shiftequivalence classes of graph derivations, is axiomatised via the construction of a free monoidal bicategory. In contrast to a previous attempt based on 2categories, the us ..."
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Cited by 18 (10 self)
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In this paper the concurrent semantics of doublepushout (DPO) graph rewriting, which is classically defined in terms of shiftequivalence classes of graph derivations, is axiomatised via the construction of a free monoidal bicategory. In contrast to a previous attempt based on 2categories, the use of bicategories allows to define rewriting on concrete graphs. Thus, the problem of composition of isomorphism classes of rewriting sequences is avoided. Moreover, as a first step towards the recovery of the full expressive power of the formalism via a purely algebraic description, the concept of disconnected rules is introduced, i.e., rules whose interface graphs are made of disconnected nodes and edges only. It is proved that, under reasonable assumptions, rewriting via disconnected rules enjoys similar concurrency properties like in the classical approach.
Concatenable graph processes: relating processes and derivation traces
 IN PROCEEDINGS OF ICALP’98, VOLUME 1443 OF LNCS
, 1998
"... Several formal concurrent semantics have been proposed for graph rewriting, a powerful formalism for the specification of concurrent and distributed systems which generalizes P/T Petri nets. In this paper we relate two such semantics recently proposed for the algebraic doublepushout approach to gra ..."
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Cited by 17 (13 self)
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Several formal concurrent semantics have been proposed for graph rewriting, a powerful formalism for the specification of concurrent and distributed systems which generalizes P/T Petri nets. In this paper we relate two such semantics recently proposed for the algebraic doublepushout approach to graph rewriting, namely the derivation trace and the graph process semantics. The notion of concatenable graph process is