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PRODID:-//Google Inc//Google Calendar 70.9054//EN
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DESCRIPTION:Graph Transformation Theory and Applications seminar of IRIF
NAME:Graph Transformation Theory and Applications
REFRESH-INTERVAL:PT4H
TIMEZONE-ID:Europe/Paris
X-WR-CALDESC:Graph Transformation Theory and Applications seminar of IRIF
X-WR-CALNAME:Graph Transformation Theory and Applications
X-WR-TIMEZONE:Europe/Paris
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TZID:Europe/Paris
X-LIC-LOCATION:Europe/Paris
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DTSTART:19700329T020000
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TZNAME:CEST
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
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DTSTART:19701025T030000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:CET
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
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BEGIN:VEVENT
SUMMARY:Graph Transformation Meets Logic - Barbara König\, Fakultät für
Ingenieurwissenschaften\, Universität Duisburg-Essen\, Germany
DTSTART;TZID=Europe/Paris;VALUE=DATE-TIME:20201120T150000
DTEND;TZID=Europe/Paris;VALUE=DATE-TIME:20201120T160000
DTSTAMP;VALUE=DATE-TIME:20210128T090302Z
UID:1236
DESCRIPTION:We review the integration of (first-order) logic respectively
nested conditions into graph transformation. Conditions can serve various
purposes: they can constrain graph rewriting\, symbolically specify sets o
f graphs\, be used in query languages and in verification (for instance in
Hoare logic and for behavioural equivalence checking). \n\nIn the graph t
ransformation community the formalism of nested graph conditions has emerg
ed\, that is\, conditions which are equivalent to first-order logic\, but
directly integrate graphs and graph morphisms\, in order to express constr
aints more succinctly. \n\nIn this talk we also explain how the notion of
nested conditions can be lifted from graph transformation systems to the s
etting of reactive systems as defined by Leifer and Milner. It turns out t
hat some constructions for graph transformation systems (such as computing
weakest preconditions and strongest postconditions and showing local conf
luence by means of critical pair analysis) can be done quite elegantly in
the more general setting.\n\n[[https://www.youtube.com/watch?v=8gGWdbRt4U8
|video recording of the seminar on YouTube]]
LOCATION:(online)
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chemical Graph Transformation and Applications - Daniel Merkle & J
akob Lykke Andersen\, Department of Mathematics and Computer Science\, Uni
versity of Southern Denmark\, Odense\, Denmark
DTSTART;TZID=Europe/Paris;VALUE=DATE-TIME:20201204T150000
DTEND;TZID=Europe/Paris;VALUE=DATE-TIME:20201204T160000
DTSTAMP;VALUE=DATE-TIME:20210128T090302Z
UID:1237
DESCRIPTION:Any computational method in chemistry must choose some level o
f precision in the modeling. One choice is made in the methods of quantum
chemistry based on quantum field theory. While highly accurate\, the metho
ds are computationally very demanding\, which restricts their practical us
e to single reactions of molecules of moderate size even when run on super
computers. At the same time\, most existing computational methods for syst
ems chemistry and biology are formulated at the other abstraction extreme\
, in which the structure of molecules is represented either not at all or
in a very rudimentary fashion that does not permit the tracking of individ
ual atoms across a series of reactions.\n\nIn this talk\, we present our o
n-going work on creating a practical modelling framework for chemistry bas
ed on Double Pushout graph transformation\, and how it can be applied to a
nalyse chemical systems. We will address important technical design decisi
ons as well as the importance of methods inspired from Algorithm Engineeri
ng in order to reach the required efficiency of our implementation. We wil
l present chemically relevant features that our framework provides (e.g. a
utomatic atom tracing) as well as a set of chemical systems we investigate
d are currently investigating. If time allows we will discuss variations o
f graph transformation rule compositions and their chemical validity.\n\n\
n[[https://www.youtube.com/watch?v=mzIXfsp-eJE&t=337s|video recording of t
he seminar on YouTube]]
LOCATION:(online)
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hierarchical port graphs & PORGY - port graph rewriting as a model
ling tool - Maribel Fernandez & Bruno Pinaud\, King's College London\, UK
& Université de Bordeaux\, France
DTSTART;TZID=Europe/Paris;VALUE=DATE-TIME:20201218T150000
DTEND;TZID=Europe/Paris;VALUE=DATE-TIME:20201218T160000
DTSTAMP;VALUE=DATE-TIME:20210128T090302Z
UID:1238
DESCRIPTION:Graph rewriting systems are natural verification and validatio
n tools: they provide visual\, intuitive representations of complex system
s while specifying the dynamic behaviour of the system in a formal way. In
this talk we will describe the use of strategic port graph rewriting as a
basis for the implementation of a visual modelling tool: PORGY. We will p
resent attributed hierarchical port graphs (AHP) and a notion of strategic
AHP-rewriting as a mechanism to model the behaviour of dynamic systems. T
he system modelled is represented by an initial graph and a collection of
graph rewrite rules\, together with a user-defined strategy to control the
application of rules. The traditional operators found in strategy languag
es for term rewriting have been adapted to deal with the more general sett
ing of graph rewriting\, and some new constructs have been included in the
strategy language to deal with graph traversal and management of rewritin
g positions in the graph. In the second part of the talk\, we describe POR
GY and give examples of application in the areas of biochemistry\, social
networks and finance.\n\nThis is joint work with members of the PORGY team
at Bordeaux and King’s College London.\n\n\nZoom registration link:\n\n
https://zoom.us/meeting/register/tJ0kd--hpzMiEtcVY7TdQh-jArgpon9t-ZHw\n\nL
ink to YouTube live stream:\n\nhttps://youtu.be/D_YHlXawg9o
LOCATION:(online)
END:VEVENT
BEGIN:VEVENT
SUMMARY:Java Bytecode Verification and Manipulation based on Model Driven
Engineering - Christoph Bockisch & Gabriele Taentzer\, Fachbereich Mathema
tik und Informatik\, Philipps-Universität Marburg\, Germany
DTSTART;TZID=Europe/Paris;VALUE=DATE-TIME:20210115T150000
DTEND;TZID=Europe/Paris;VALUE=DATE-TIME:20210115T160000
DTSTAMP;VALUE=DATE-TIME:20210128T090302Z
UID:1239
DESCRIPTION:Program transformations are frequently developed\, e.g.\, to r
ealize programming language extensions or dynamic program analyses such as
profiling. They are typically implemented by manipulating bytecode as the
availability of source code is not guaranteed. There are standard librari
es such as ASM that are typically used for implementing Java bytecode mani
pulations. To check their correctness\, they are usually tested by applyin
g them to different programs\, running the manipulated programs and observ
ing their behaviors. As part of the second step\, the Java virtual machine
verifies the bytecode\, which can uncover errors in the bytecode introduc
ed by the manipulation. That approach uses different technologies that are
not well linked making the process of developing and testing bytecode man
ipulations difficult. In this talk\, we intend to perform bytecode manipul
ation by using concepts and techniques of model-driven engineering. We are
convinced that the declarative nature of model transformation rules allow
s the debugging and analyzing of bytecode manipulations in more details th
an classically done. Following this path\, a meta-model for bytecode is ne
eded including OCL constraints for bytecode verification. We show that bas
ing bytecode manipulation on model transformation can provide more immedia
te guidance and feedback to the developer\, especially when model transfor
mation is formally based on graph transformation. Bytecode verification ca
n take place directly in the manipulated model with the help of OCL checki
ng\, eliminating the need to use multiple technologies. In some cases\, it
is even possible to automatically determine application conditions under
which bytecode manipulations are correct by construction\; then bytecode v
erification after a bytecode manipulation can be avoided altogether.\n\n\n
[[https://zoom.us/meeting/register/tJwvd-2przwoEtUP5siUVsU2taD4rolKbWTd|Zo
om registration]]\n\n[[https://youtu.be/glboPhoWFXw|YouTube live stream]]
LOCATION:(online)
END:VEVENT
BEGIN:VEVENT
SUMMARY:MDEOptimiser: Searching for optimal models with EMF and Henshin -
Steffen Zschaler\, Department of Informatics\, King's College London\, UK
DTSTART;TZID=Europe/Paris;VALUE=DATE-TIME:20210212T150000
DTEND;TZID=Europe/Paris;VALUE=DATE-TIME:20210212T160000
DTSTAMP;VALUE=DATE-TIME:20210128T090302Z
UID:1240
DESCRIPTION:An overview presentation of the work we have been doing over t
he past years on MDEOptimiser\, a tool that uses evolutionary search over
EMF models to solve multi-objective optimisation problems. Graph transform
ations are used to encode mutation operators\, opening interesting opportu
nities for automatically generating domain-specific mutation operators.
LOCATION:(online)
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fast Graph Programs - Detlef Plump & Graham Campbell\, University
of York\, UK & Newcastle University\, UK
DTSTART;TZID=Europe/Paris;VALUE=DATE-TIME:20210226T150000
DTEND;TZID=Europe/Paris;VALUE=DATE-TIME:20210226T160000
DTSTAMP;VALUE=DATE-TIME:20210128T090302Z
UID:1241
DESCRIPTION:This will be an overview of our ongoing work on fast graph pro
grams in the language GP 2. We will present programs which in some cases m
atch the time complexity of graph algorithms in imperative languages. In o
ther cases we need to assume that input graphs have a bounded degree\, to
reach the speed of conventional algorithms.
LOCATION:(online)
END:VEVENT
BEGIN:VEVENT
SUMMARY:Confluence of Graph Transformation - Leen Lambers & Fernando Oreja
s\, Hasso-Plattner-Institut Potsdam\, Germany & Technical University of Ca
talonia (UPC)\, Spain
DTSTART;TZID=Europe/Paris;VALUE=DATE-TIME:20210129T150000
DTEND;TZID=Europe/Paris;VALUE=DATE-TIME:20210129T160000
DTSTAMP;VALUE=DATE-TIME:20210128T090302Z
UID:1251
DESCRIPTION:Confluence has been studied for graph transformation since sev
eral decades now. Confluence analysis has been applied\, for example\, to
determining uniqueness of model transformation results in model-driven en
gineering. It is strongly related to conflict analysis for graph transfor
mation\, i.e. detecting and inspecting all possible conflicts that may occ
ur for a given set of graph transformation rules. The latter finds applica
tions\, for example\, in software analysis and design. Both conflict and
confluence analysis rely on the existence and further analysis of a finite
and representative set of conflicts for a given set of graph transformati
on rules.\n\nTraditionally\, the set of critical pairs has been shown to c
onstitute such a set. It is representative in the sense that for each conf
lict a critical pair exists\, representing the conflict in a minimal conte
xt\, such that it can be extended injectively to this conflict (M-complete
ness). Recently\, it has been shown that initial conflicts constitute a co
nsiderably reduced subset of critical pairs\, being still representative i
n a slightly different way. In particular\, for each conflict there exist
s a unique initial conflict that can be extended (possibly non-injectively
) to the given conflict (completeness). Compared to the set of critical p
airs\, the smaller set of initial conflicts allows for more efficient conf
lict as well as confluence analysis.\n\nWe continue by demonstrating that
initial conflicts (critical pairs) are minimally complete (resp. minimally
M-complete)\, and thus are both optimally reduced w.r.t. representing con
flicts in a minimal context via general (resp. injective) extension morphi
sms. We proceed with showing that it is impossible to generalize this resu
lt to the case of rules with application conditions (equivalent to FOL on
graphs). We therefore revert to a symbolic setting\, where finiteness and
minimal (M-)completeness can again be guaranteed. Finally\, we describe
important special cases (e.g. rules with negative application conditions)\
, where we are able to obtain minimally complete (resp. M-complete) sets o
f conflicts in the concrete setting again.\n\n\n[[https://zoom.us/meeting/
register/tJIrd-ihrzgqHdO7-bPkhQG92mDpzKdIBCHb|Zoom registration]]\n\n[[htt
ps://youtu.be/Um90A_lk4ik|YouTube live stream]]
LOCATION:(online)
END:VEVENT
BEGIN:VEVENT
SUMMARY:Composition-based Graph Rewriting - Jean-Pierre Jouannaud\, Labora
toire d'Informatique (LIX)\, École Polytechnique
DTSTART;TZID=Europe/Paris;VALUE=DATE-TIME:20210312T150000
DTEND;TZID=Europe/Paris;VALUE=DATE-TIME:20210312T160000
DTSTAMP;VALUE=DATE-TIME:20210128T090302Z
UID:1252
DESCRIPTION:Double Pushout (DPO) rewriting\, the dominant model for graph
rewriting\, emerged in the early 70’s\, strongly influenced at that time
by graph grammars. Developed by Hartmut Ehrig and his many collaborators\
, graph rewriting was from the beginning based on category theory\, with t
he major insight that the two basic rewriting constructions\, namely match
ing and replacement\, were intimately related to graph morphisms and their
pushouts. A new model has emerged recently\, so-called Composition based
rewriting (Core)\, in which rewriting is based on a composition operator o
ver directed rooted labelled graphs (drags)\, so that matching a drag G ag
ainst a drag L amounts to compose L with some context drag C\, and rewriti
ng G with L -> R to compose R with C. We will describe Core for drags befo
re to relate it precisely to DPO and extend it to adhesive categories of g
raphs and beyond. We will also show how to define composition abstractly i
n any category of graphs satisfying appropriate properties among which adh
esivity (wrt monomorphisms). Major differences between DPO and Core will b
e discussed. \n\n\nZoom registration link: TBA\n\nLink to YouTube live str
eam: TBA
LOCATION:(online)
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