Results 1  10
of
75
Automatic verification of datacentric business processes
 In ICDT
, 2009
"... We formalize and study business process systems that are centered around "business artifacts", or simply "artifacts". Artifacts are used to represent (real or conceptual) key business entities, including both their data schema and lifecycles. The lifecycle of an artifact type spe ..."
Abstract

Cited by 86 (28 self)
 Add to MetaCart
We formalize and study business process systems that are centered around "business artifacts", or simply "artifacts". Artifacts are used to represent (real or conceptual) key business entities, including both their data schema and lifecycles. The lifecycle of an artifact type specifies the possible sequencings of services that can be applied to an artifact of this type as it progresses through the business process. The artifactcentric approach was introduced by IBM, and has been used to achieve substantial savings when performing business transformations. In this paper, artifacts carry attribute records and internal state relations (holding sets of tuples) that services can consult and update. In addition, services can access an underlying database and can introduce new values from an infinite domain, thus modeling external inputs or partially specified processes described by preandpost
Twovariable logic on data trees and XML reasoning
"... Motivated by reasoning tasks for XML languages, the satisfiability problem of logics on data trees is investigated. The nodes of a data tree have a label from a finite set and a data value from a possibly infinite set. It is shown that satisfiability for twovariable firstorder logic is decidable i ..."
Abstract

Cited by 84 (17 self)
 Add to MetaCart
Motivated by reasoning tasks for XML languages, the satisfiability problem of logics on data trees is investigated. The nodes of a data tree have a label from a finite set and a data value from a possibly infinite set. It is shown that satisfiability for twovariable firstorder logic is decidable if the tree structure can be accessed only through the child and the next sibling predicates and the access to data values is restricted to equality tests. From this main result, decidability of satisfiability and containment for a dataaware fragment of XPath and of the implication problem for unary key and inclusion constraints is concluded.
Verification of relational datacentric dynamic systems with external services
, 2013
"... Datacentric dynamic systems are systems where both the process controlling the dynamics and the manipulation of data are equally central. We study verification of (firstorder) µcalculus variants over relational datacentric dynamic systems, where data are maintained in a relational database, and ..."
Abstract

Cited by 51 (20 self)
 Add to MetaCart
(Show Context)
Datacentric dynamic systems are systems where both the process controlling the dynamics and the manipulation of data are equally central. We study verification of (firstorder) µcalculus variants over relational datacentric dynamic systems, where data are maintained in a relational database, and the process is described in terms of atomic actions that evolve the database. Action execution may involve calls to external services, thus inserting fresh data into the system. As a result such systems are infinitestate. We show that verification is undecidable in general, and we isolate notable cases where decidability is achieved. Specifically we start by considering service calls that return values deterministically (depending only on passed parameters). We show that in a µcalculus variant that preserves knowledge of objects appeared along a run we get decidability under the assumption that the fresh data introduced along a
Static analysis of Active XML systems
 in PODS, 2008
"... Active XML is a highlevel specification language tailored to dataintensive, distributed, dynamic Web services. Active XML is based on XML documents with embedded function calls. The state of a document evolves depending on the result of internal function calls (local computations) or external ones ..."
Abstract

Cited by 35 (15 self)
 Add to MetaCart
(Show Context)
Active XML is a highlevel specification language tailored to dataintensive, distributed, dynamic Web services. Active XML is based on XML documents with embedded function calls. The state of a document evolves depending on the result of internal function calls (local computations) or external ones (interactions with users or other services). Function calls return documents that may be active, so may activate new subtasks. The focus of the paper is on the verification of temporal properties of runs of Active XML systems, specified in a treepattern based temporal logic, TreeLTL, that allows expressing a rich class of semantic properties of the application. The main results establish the boundary of decidability and the complexity of automatic verification of TreeLTL properties. 1
Twovariable logic on data words
, 2007
"... In a data word each position carries a label from a finite alphabet and a data value from some infinite domain. These models have been already considered in the realm of semistructured data, timed automata and extended temporal logics. It is shown that satisfiability for the twovariable firstorder ..."
Abstract

Cited by 35 (4 self)
 Add to MetaCart
In a data word each position carries a label from a finite alphabet and a data value from some infinite domain. These models have been already considered in the realm of semistructured data, timed automata and extended temporal logics. It is shown that satisfiability for the twovariable firstorder logic FO 2 (∼,<,+1) is decidable over finite and over infinite data words, where ∼ is a binary predicate testing the data value equality and +1, < are the usual successor and order predicates. The complexity of the problem is at least as hard as Petri net reachability. Several extensions of the logic are considered, some remain decidable while some are undecidable.
Automata with group actions
 In LICS
, 2011
"... Abstract—Our motivating question is a MyhillNerode theorem for infinite alphabets. We consider several kinds of those: alphabets whose letters can be compared only for equality, but also ones with more structure, such as a total order or a partial order. We develop a framework for studying such alp ..."
Abstract

Cited by 33 (8 self)
 Add to MetaCart
(Show Context)
Abstract—Our motivating question is a MyhillNerode theorem for infinite alphabets. We consider several kinds of those: alphabets whose letters can be compared only for equality, but also ones with more structure, such as a total order or a partial order. We develop a framework for studying such alphabets, where the key role is played by the automorphism group of the alphabet. This framework builds on the idea of nominal sets of Gabbay and Pitts; nominal sets are the special case of our framework where letters can be only compared for equality. We use the framework to uniformly generalize to infinite alphabets parts of automata theory, including decidability results. In the case of letters compared for equality, we obtain automata equivalent in expressive power to finite memory automata, as defined by Francez and Kaminski. I.
Revisiting Ackermannhardness for lossy counter machines and reset Petri nets
 Procs. MFCS2010, volume 6281 of LNCS
, 2010
"... www.lsv.enscachan.fr/~phs Abstract. We prove that coverability and termination are not primitiverecursive for lossy counter machines and for Reset Petri nets. 1 ..."
Abstract

Cited by 31 (1 self)
 Add to MetaCart
(Show Context)
www.lsv.enscachan.fr/~phs Abstract. We prove that coverability and termination are not primitiverecursive for lossy counter machines and for Reset Petri nets. 1
On notions of regularity for data languages
 In FCT
, 2007
"... Motivated by considerations in XML database theory and model checking, data strings have been introduced as an extension of finite alphabet strings which carry, at each position, a symbol and a data value from an infinite domain. Previous work has shown that it is difficult to come up with an expres ..."
Abstract

Cited by 28 (5 self)
 Add to MetaCart
(Show Context)
Motivated by considerations in XML database theory and model checking, data strings have been introduced as an extension of finite alphabet strings which carry, at each position, a symbol and a data value from an infinite domain. Previous work has shown that it is difficult to come up with an expressive yet decidable automaton model for data languages. Recently, such a model, data automata, was introduced. This paper introduces a simpler but equivalent model and investigates its expressive power, algorithmic and closure properties, and some extensions. 1
Alternationfree modal mucalculus for data trees
 In LICS’07
, 2007
"... An alternationfree modal µcalculus over data trees is introduced and studied. A data tree is an unranked ordered tree whose every node is labelled by a letter from a finite alphabet and an element (“datum”) from an infinite set. For expressing datasensitive properties, the calculus is equipped wi ..."
Abstract

Cited by 27 (3 self)
 Add to MetaCart
(Show Context)
An alternationfree modal µcalculus over data trees is introduced and studied. A data tree is an unranked ordered tree whose every node is labelled by a letter from a finite alphabet and an element (“datum”) from an infinite set. For expressing datasensitive properties, the calculus is equipped with freeze quantification. A freeze quantifier stores in a register the datum labelling the current tree node, which can then be accessed for equality comparisons deeper in the formula. The main results in the paper are that, for the fragment with forward modal operators and one register, satisfiability over finite data trees is decidable but not primitive recursive, and that for the subfragment consisting of safety formulae, satisfiability over countable data trees is decidable but not elementary. The proofs use alternating tree automata which have registers, and establish correspondences with nondeterministic tree automata which have faulty counters. Allowing backward modal operators or two registers causes undecidability. As consequences, decidability is obtained for two datasensitive fragments of the XPath query language. The paper shows that, for reasoning about data trees, the forward fragment of the calculus with one register is a powerful alternative to a recently proposed firstorder logic with two variables. 1.
Complexity of data tree patterns over XML documents
 in Mathematical Foundations of Computer Science (MFCS), ser. Lecture Notes in Computer Science
, 2008
"... Abstract. We consider Boolean combinations of data tree patterns as a specification and query language for XML documents. Data tree patterns are tree patterns plus variable (in)equalities which express joins between attribute values. Data tree patterns are a simple and natural formalism for expressi ..."
Abstract

Cited by 23 (3 self)
 Add to MetaCart
(Show Context)
Abstract. We consider Boolean combinations of data tree patterns as a specification and query language for XML documents. Data tree patterns are tree patterns plus variable (in)equalities which express joins between attribute values. Data tree patterns are a simple and natural formalism for expressing properties of XML documents. We consider first the model checking problem (query evaluation), we show that it is DPcomplete 1 in general and already NPcomplete when we consider a single pattern. We then consider the satisfiability problem in the presence of a DTD. We show that it is in general undecidable and we identify several decidable fragments. 1