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23
Canonical Graph Shapes
 Programming Languages and Systems — European Symposium on Programming (ESOP
, 2004
"... Graphs are an intuitive model for states of a (software) system that include pointer structures  for instance, objectoriented programs. ..."
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Cited by 30 (13 self)
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Graphs are an intuitive model for states of a (software) system that include pointer structures  for instance, objectoriented programs.
Counterexampleguided abstraction refinement for the analysis of graph transformation systems
 IN: PROC. OF TACAS ’06
, 2006
"... Graph transformation systems are a general specification language for systems with dynamically changing topologies, such as mobile and distributed systems. We propose a counterexampleguided abstraction refinement technique which is based on the overapproximation of graph transformation systems ( ..."
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Cited by 27 (3 self)
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Graph transformation systems are a general specification language for systems with dynamically changing topologies, such as mobile and distributed systems. We propose a counterexampleguided abstraction refinement technique which is based on the overapproximation of graph transformation systems (gts) by Petri nets. We show that a spurious counterexample is caused by merging nodes during the approximation. We present a technique for identifying these merged nodes and splitting them using abstraction refinement, which removes the spurious run. The technique has been implemented in the Augur tool and experimental results are discussed.
A Framework for the Verification of InfiniteState Graph Transformation Systems
, 2008
"... We propose a technique for the analysis of infinitestate graph transformation systems, based on the construction of finite structures approximating their behaviour. Following a classical approach, one can construct a chain of finite underapproximations (ktruncations) of the Winskel style unfolding ..."
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Cited by 17 (3 self)
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We propose a technique for the analysis of infinitestate graph transformation systems, based on the construction of finite structures approximating their behaviour. Following a classical approach, one can construct a chain of finite underapproximations (ktruncations) of the Winskel style unfolding of a graph grammar. More interestingly, also a chain of finite overapproximations (kcoverings) of the unfolding can be constructed. The fact that ktruncations and kcoverings approximate the unfolding with arbitrary accuracy is formalised by showing that both chains converge (in a categorical sense) to the full unfolding. We discuss how the finite over and underapproximations can be used to check properties of systems modelled by graph transformation systems, illustrating this with some small examples. We also describe the Augur tool, which provides a partial implementation of the proposed constructions, and has been used for the verification of larger case studies.
Weakest preconditions for highlevel programs
 In Proc. Graph Transformations (ICGT 2006
, 2006
"... Abstract In proof theory, a standard method for showing the correctness of a program w.r.t. given pre and postconditions is to construct a weakest precondition and to show that the precondition implies the weakest precondition. In this paper, graph programs in the sense of Habel and Plump 2001 ar ..."
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Cited by 11 (5 self)
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Abstract In proof theory, a standard method for showing the correctness of a program w.r.t. given pre and postconditions is to construct a weakest precondition and to show that the precondition implies the weakest precondition. In this paper, graph programs in the sense of Habel and Plump 2001 are extended to programs over highlevel rules with application conditions, a formal definition of weakest preconditions for highlevel programs in the sense of Dijkstra 1975 is given, and a construction of weakest preconditions is presented. 1
Expressiveness of graph conditions with variables
, 2010
"... Graph conditions are very important for graph transformation systems and graph programs in a large variety of application areas. Nevertheless, nonlocal graph properties like “there exists a path”, “the graph is connected”, and “the graph is cyclefree ” are not expressible by finite graph conditio ..."
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Cited by 10 (4 self)
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Graph conditions are very important for graph transformation systems and graph programs in a large variety of application areas. Nevertheless, nonlocal graph properties like “there exists a path”, “the graph is connected”, and “the graph is cyclefree ” are not expressible by finite graph conditions. In this paper, we generalize the notion of finite graph conditions, expressively equivalent to firstorder formulas on graphs, to finite HR+ graph conditions, i.e., finite graph conditions with variables where the variables are placeholders for graphs generated by a hyperedge replacement system. We show that graphs with variables and replacement morphisms form a weak adhesive HLR category. We investigate the expressive power of HR+ graph conditions and show that finite HR+ graph conditions are more expressive than monadic secondorder graph formulas.
A temporal graph logic for verification of graph transformation systems
 IN PROCEEDINGS OF WADT’06
, 2007
"... We extend our approach for verifying properties of graph transformation systems using suitable abstractions. In the original approach properties are specified as formulae of a propositional temporal logic whose atomic predicates are monadic secondorder graph formulae. We generalize this aspect by ..."
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Cited by 9 (3 self)
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We extend our approach for verifying properties of graph transformation systems using suitable abstractions. In the original approach properties are specified as formulae of a propositional temporal logic whose atomic predicates are monadic secondorder graph formulae. We generalize this aspect by considering more expressive logics, where edge quantifiers and temporal modalities can be interleaved, a feature which allows, e.g., to trace the history of objects in time. After characterizing fragments of the logic which can be safely checked on the approximations, we show how the verification of the logic over graph transformation systems can be reduced to the verification of a logic over suitably defined Petri nets.
Formal consistency verification between bpel process and privacy policy
 In Privacy Security and Trust
, 2006
"... Despite the increased privacy concerns in the Internet, not much attention has been paid into enforcing privacy policies of organisations who collect and consume personal data using automatic means (e.g., Web services). In this paper, we propose a graphtransformation based framework to check whethe ..."
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Cited by 6 (2 self)
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Despite the increased privacy concerns in the Internet, not much attention has been paid into enforcing privacy policies of organisations who collect and consume personal data using automatic means (e.g., Web services). In this paper, we propose a graphtransformation based framework to check whether an internal business process (implemented using a standard Web service composition language such as BPEL) adheres to the organisation’s privacy policies. The graphbased specification formalism combines the advantages of an intuitive visual framework with rigorous semantical foundation that allows consistency checking between a business process and privacy policy. The privacy consistency verification framework is defined by a set of rules to build the system state and sets of constraints (positive and negative) to specify the wanted and unwanted substates. 1
Augur 2  a new version of a tool for the analysis of graph transformation systems
 IN PROC. WORKSHOP ON GRAPH TRANSFORMATION AND VISUAL MODELING TECHNIQUES (GTVMT’06), ENTCS
, 2006
"... We describe the design and the present state of the verification tool Augur 2 which is currently being developed. It is based on Augur 1, a tool which can analyze graph transformation systems by approximating them by Petri nets. The main reason for the new development was to create an open, flexible ..."
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Cited by 6 (0 self)
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We describe the design and the present state of the verification tool Augur 2 which is currently being developed. It is based on Augur 1, a tool which can analyze graph transformation systems by approximating them by Petri nets. The main reason for the new development was to create an open, flexible and extensible verification environment. Also, compared to the previous version, Augur 2 will include more functionality and new analysis techniques.