2,808 research outputs found
Ten virtues of structured graphs
This paper extends the invited talk by the first author about the virtues
of structured graphs. The motivation behind the talk and this paper relies on our
experience on the development of ADR, a formal approach for the design of styleconformant,
reconfigurable software systems. ADR is based on hierarchical graphs
with interfaces and it has been conceived in the attempt of reconciling software architectures
and process calculi by means of graphical methods. We have tried to
write an ADR agnostic paper where we raise some drawbacks of flat, unstructured
graphs for the design and analysis of software systems and we argue that hierarchical,
structured graphs can alleviate such drawbacks
Bidirectional Transformation "bx" (Dagstuhl Seminar 11031)
Bidirectional transformations bx are a mechanism for maintaining the
consistency of two (or more) related sources of information. Researchers from
many different areas of computer science including databases (DB), graph
transformations (GT), software engineering (SE), and programming languages (PL)
are actively investigating the use of bx to solve a diverse set of
problems. Although researchers have been actively working on bidirectional
transformations in the above mentioned communities for many years already, there
has been very little cross-discipline interaction and cooperation so far. The
purpose of a first International Meeting on Bidirectional Transformations (GRACE-BX), held in December 2008 near Tokyo, was therefore to bring together international elites, promising young researchers, and leading practitioners to share problems, discuss solutions, and open a dialogue towards understanding the common underpinnings of bx in all these areas. While the GRACE-BX meeting provided a starting point for exchanging ideas in different communities and confirmed our believe that there is a considerable overlap of studied problems and developed solutions in the identified communities, the Dagstuhl Seminar 11031 on ``Bidirectional Transformations\u27\u27 also aimed at providing a place for working together to define a common vocabulary of terms and desirable properties of bidirectional transformations, develop a suite of
benchmarks, solve some challenging problems, and launch joint efforts to form a
living bx community of cooperating experts across the identified
subdisciplines. This report documents the program and the outcomes of Dagstuhl
Seminar 11031 with abstracts of tutorials, working groups, and presentations on
specific research topics
A Graph Rewriting Approach for Transformational Design of Digital Systems
Transformational design integrates design and verification. It combines âcorrectness by constructionâ and design creativity by the use of pre-proven behaviour preserving transformations as design steps. The formal aspects of this methodology are hidden in the transformations. A constraint is the availability of a design representation with a compositional formal semantics. Graph representations are useful design representations because of their visualisation of design information. In this paper graph rewriting theory, as developed in the last twenty years in mathematics, is shown to be a useful basis for a formal framework for transformational design. The semantic aspects of graphs which are no part of graph rewriting theory are included by the use of attributed graphs. The used attribute algebra, table algebra, is a relation algebra derived from database theory. The combination of graph rewriting, table algebra and transformational design is new
A PBPO+ Graph Rewriting Tutorial
We provide a tutorial introduction to the algebraic graph rewriting formalism
PBPO+. We show how PBPO+ can be obtained by composing a few simple building
blocks, and model the reduction rules for binary decision diagrams as an
example. Along the way, we comment on how alternative design decisions lead to
related formalisms in the literature, such as DPO. We close with a detailed
comparison with Bauderon's double pullback approach.Comment: In Proceedings TERMGRAPH 2022, arXiv:2303.1421
DPO Rewriting and Abstract Semantics via Opfibrations
AbstractThe classical DPO graph rewriting construction is re-expressed using the opfibration approach introduced originally for term graph rewriting. Using a skeleton category of graphs, a base of canonical graphs-in-context, with DPO rules as arrows, and with categories of redexes over each object in the base, yields a category of rewrites via the discrete Grothendieck construction. The various possible ways of combining rules and rewrites leads to a variety of functors amongst the various categories formed. Categories whose arrows are rewriting sequences have counterparts where the arrows are elementary event structures, and an event structure semantics for arbitrary graph grammars emerges naturally
On Some Closure Properties of nc-eNCE Graph Grammars
In the study of automata and grammars, closure properties of the associated
languages have been studied extensively. In particular, closure properties of
various types of graph grammars have been examined in (Rozenberg and Welzl,
Inf. and Control,1986) and (Rozenberg and Welzl, Acta Informatica,1986). In
this paper we examine some critical closure properties of the nc-eNCE graph
grammars discussed in (Jayakrishna and Mathew, Symmetry 2023) and (Jayakrishna
and Mathew, ICMICDS 2022).Comment: 14 pages,9 figures, to be submitted to Theory of Computin
Constraint validation support in visual model transformation systems
Model-Driven Architecture (MDA) standardized by OMG facilitates to separate the platform independent part and the platform specific part of a system model. Due to this separation Platform-Independent Model (PIM) can be reused across several implementation platforms of the system. Platform-Specific Model (PSM) is ideally generated automatically from PIM via model transformation steps. Because of the appearance of high level languages, object-oriented technologies and CASE tools, metamodeling becomes more and more important. Metamodeling is one of the most central techniques both in design of visual languages, and reuse existing domains by extending the metamodel level. The creation of model compliers on a metamodeling basis is illustrated by a software package called Visual Modeling and Transformation System (VMTS), which is an n-layer multipurpose modeling and metamodel-based transformation system. VMTS is able to realize an MDA model compiler. This paper (i) addresses the relationship between the constraints enlisted in metamodel-based rewriting rules and the pre- and postconditions, (ii) it introduces the concepts of general validation, general preservation and general guarantee, which facilitate that if a transformation step is specified adequately with the help of constraints, and the step has been executed successfully for the input model, then the generated output model is in accordance with the expected result, which is described by the transformation step refined with the constraints. An illustrative case study based on constraint specification in rewriting rules is also provided
- âŚ