H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. In E. Astesiano, G. Reggio, and A. Tarlecki, editors, Recent Trends in Data Types Specification, pages 219--235. Springer-Verlag, Berlin, LNCS 906, 1995.  Home/Search   Document Details and Download   Summary   Related Articles   Check

.... Phi) where Sigma = Id; Ac) is a signature, consisting of a set Id of identities and an Id indexed set family Ac = fAc i g i2Id of action symbols. Phi = f Phi i g i2Id in an Id indexed set family of formulae. The detailed construction of Sigma from a given Troll specification is given in [17]. Models of single objects are labelled sequential event structures and models of systems are labelled event structures [17] Before defining models of single objects we give the basic definition of sequential event structures. A sequential event structure is a triple E = Ev; #) Ev is a ....

....i g i2Id of action symbols. Phi = f Phi i g i2Id in an Id indexed set family of formulae. The detailed construction of Sigma from a given Troll specification is given in [17] Models of single objects are labelled sequential event structures and models of systems are labelled event structures [17]. Before defining models of single objects we give the basic definition of sequential event structures. A sequential event structure is a triple E = Ev; #) Ev is a set of events, is a partial order (causality) and # is a reflexive symmetric order (conflict) Moreover satisfies ....

H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. In E. Astesiano, G. Reggio, and A. Tarlecki, editors, Recent Trends in Data Types Specification, Proc. 10th Workshop on Specification of Abstract Data Types joint with the 5th COMPASS Workshop, S.Margherita, Italy, May/June

....logic and PROLOG is a well known logic programming language. However, temporal logics are a means for the descriptive specification of the behaviour of reactive and concurrent system [22, 25] We use a linear temporal logic (DTL: Distributed Temporal Logic) to specify information system dynamics [11, 12]. The design of this logic has been influenced by the n agent logic [21] Major problems arise when temporal logics is combined with reification. This is due to the fact that temporal operators like next and yesterday (among others) assume a specific time scale where each action execution ....

....is done on top of a given data signature. Here we do not present the data signature part since it is not necessary for understanding this paper, but would needlessly increase the complexity. The interested reader may find the detailed construction of a signature for a given Troll specification in [11]. For the structural part of our example we yield the following: Example 2 (insurance company structural part) The statical part of insurance company specification SysSpec InsuranceCompany = Sigma ; Phi) is given as Sigma = Id; Att; Ac) where Id = fE; Cg, Att = Att E [ Att C = ....

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Ehrich, H.-D., Sernadas, A.: Local Specification of Distributed Families of Sequential Objects. In E. Astesiano, G. Reggio, and A. Tarlecki, editors, Recent Trends in Data Types Specification, Proc. 10th Workshop on Specification of Abstract Data Types joint with the 5th COMPASS Workshop, S.Margherita, Italy, May/June

....be discussed. Both specifications will be refined into more detailed ones and given a common event based semantics via the process algebraic specification. Our semantics is deadlock sensitive and compositional which is the main difference to the Troll semantics as it was originally defined in [ES95] The existing theories are then applied to derive restrictions on the refinement. In case of object orientation necessary conditions for refinements to be correct w.r.t. preservation of properties are given. In case of process algebras the given conditions are necessary and sufficient. On the ....

....J1(sum1) jj J2(sum2) The agents are then combined into the casino. Initially the system is created by Casino = P1 jj P2 jj SM(0; 0) 2. 4 Semantics For systems of sequential agents as well as for Troll a causality based semantics similar to Winskel s event structures [Win87] is given in [Huh95, ES95] But in contrary to the original Troll semantics [ES95] in the semantics for systems of sequential agents deadlocks are modelled explicitly. Thus we found this semantics more appropriate to reason about action refinement when synchronisation has to be taken into account. A Troll specification ....

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H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. In E. Astesiano, G. Reggio, and A. Tarlecki, editors, Recent Trends in Data Types Specification, Proc. 10th Workshop on Specification of Abstract Data Types joint with the 5th COMPASS Workshop, S.Margherita, Italy, May/June

....be discussed. Both specifications will be refined into more detailed ones and given a common event based semantics via the process algebraic specification. This semantics is deadlock sensitive and compositional which is the main difference to the Troll semantics as it was originally defined in [ES95] The existing theory is then applied to derive the necessary restrictions on the refinement. On the common semantic basis the derived conditions for correct refinements can be compared. It turns out that the process algebraic conditions are more specific in that a broader class of refinements ....

....its alphabet. The agents are then combined into the casino. Initially the system is created by Casino = P1 jj P2 jj J1(0) jj J2(0) 2. 3 Semantics For systems of sequential agents as well as for Troll a causality based semantics similiar to Winskel s event structures [Win87] is given in [Huh96, ES95] Both in the process algebraic and the object oriented specification a set of objects or agents together with a distributed alphabet is used. The event structure semantics of Troll specifications is derived by first computing the set of all possible behaviours and then removing all executions ....

[Article contains additional citation context not shown here]

H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. In E. Astesiano et al., editor, Recent Trends in Data Types Specification, pages 219--235. LNCS 906, 1995.

....in database theory. For example Schewe, Schmidt and Wetzel [SSW91] outline a set of standard refinement rules to support the steps from conceptual database design to efficient extended relational implementations. Object oriented investigations have also been made, e.g. SGG 91, SGS92, ES90] give semantic foundations of reification of (abstract) objects over (a community of base) objects. The work in [FM90, FSMS92] also deals with implementing objects. In [FM94] actions are considered as objects and by means of this the refinement of atomic actions by continuing transactions is ....

....should happen synchronously. Correspondingly, semantics is given to systems of objects by global webs which are composed of the local life cycles glued together at shared communication events. This semantic approach fits into the more general framework of locally sequential event structures. In [ES95] one can find the detailed definitions of the chosen model of locally sequential event structures and the distributed temporal logic (DTL) going with this model. Moreover, some general results about the mathematics of this semantic framework are presented in [ES95] DTL is a modification of the ....

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H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. This volume.

....by PTB In this paper we present our problem domain and our specification language Troll which we use to design an information system in an industrial environment. The Troll approach incorporates many ideas which have been developed over the past 8 years. Much work in the theoretical foundations [13, 3, 4] and on methodological [11, 12, 6] issues has been done. Moreover, the first step to develop the method is based on Troll. In the next section we describe our problem domain. 2 Description of the problem domain In this Section we want to give some ideas about important aspects of our specific ....

H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. In E. Astesiano, G. Reggio, and A. Tarlecki, editors, Recent Trends in Data Types Specification, Proc. 10th Workshop on Specification of Abstract Data Types joint with the 5th COMPASS Workshop, S.Margherita, Italy, May/June

....SD is a set of data sorts, and# D an S # D SD indexed family of sets of 5 operation symbols. Examples of data sorts are boolean, integer, string, setOfString, and so on. An extended data signature extends #D with object sorts and operations on them. Extended data signatures are defined in [ES95] to deal with object specification. Let # = S, ## be an extended data signature of #D , where S is a set of sorts (data and object sorts, that is, S = SD # SO ) and# an S # S indexed family of sets of operation symbols such that# D # ## Let X = X s s#S be an S indexed family of ....

....and object sorts, that is, S = SD # SO ) and# an S # S indexed family of sets of operation symbols such that# D # ## Let X = X s s#S be an S indexed family of sets of variables. The interpretation structures for extended data signatures are # algebras. For more details consult [ES95] At a certain module level l, we have a finite set of modules given by Mod l = 1, n . Let m # Mod l . A module signature for m at level l is given by # l m = #m , Id m , Atm , Acm ) where #m is an extended data signature as described above; Id m = Id ms s#SO is an SO ....

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H.-D. Ehrich and A. Sernadas. Local specification of distributed families of sequential objects. In E. Astesiano, G. Reggio, and 25 A. Tarlecki, editors, Recent Trends in Data Types Specification, volume 906 of Lecture Notes in Computer Science, pages 219-- 235. Springer-Verlag, Berlin, 1995.

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H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. In E. Astesiano, G. Reggio, and A. Tarlecki, editors, Recent Trends in Data Types Specification, pages 219--235. Springer-Verlag, Berlin, LNCS 906, 1995.

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H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. In E. Astesiano, G. Reggio, and A. Tarlecki, editors, Recent Trends in Data Types Specification, Proc. 10th Workshop on Specification of Abstract Data Types joint with the 5th COMPASS Workshop, S.Margherita, Italy, May/June 1994, Selected papers, pages 219--235. Springer, Berlin, LNCS 906, 1995.

.... e 2 . That means that successor events are distinguishable by their labels. Definite sequential behaviors can be uniquely characterized by their label sequences. This is why much of the earlier work on sequential object theory is based on label sequences rather than event structures (cf. e.g. [ESS90, EJDS94] Behavior morphisms. Behaviors are related by behavior morphisms which are event structure morphisms preserving labels in a canonical way. Definition 8. Let B i = E 1 ; 1 ; P 1 ) and B i = E 2 ; 2 ; P 2 ) be behaviors. A behavior morphism f : B 1 B 2 is pair f = g; h) where g : ....

....Tbench will be extended towards capturing distribution, based on distributed temporal logic. The underlying theory has to be elaborated and refined, a more detailed account will appear in [Ehr96] Special aspects of Dtl and its use for describing semantics of distributed systems can be found in [ES95] Further research will focus on interaction and modularization concepts. Dtl describes synchronous and symmetric interaction, albeit from a local point of view. On the Troll language level, a richer spectrum of interaction concepts is envisaged, including modes of asynchronous directed ....

Ehrich, H.-D. and Sernadas, A. Local Specification of Distributed Families of Sequential Objects. In Astesiano, E., Reggio, G., and Tarlecki, A., editors, Recent Trends in Data Types Specification, Proc. 10th Workshop on Specification of Abstract Data Types joint with the 5th COMPASS Workshop, S.Margherita, Italy, May/June

No context found.

H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. In E. Astesiano, G. Reggio, and A. Tarlecki, editors, Recent Trends in Data Types Specification, Proc. 10th Workshop on Specification of Abstract Data Types joint with the 5th COMPASS Workshop , S.Margherita, Italy, May/June

....still cope with a low level of abstraction. We decided to apply the formal and object oriented specification language Troll [JSHS96] The Troll approach incorporates many ideas which have been developed over the past 8 years. Much work in the theoretical foundations [SSE87, ESS88, EJDS94, DE95, ES95] and on methodological [SJ92, SJH93, HJ95] issues has been done. The Troll approach supports the declarative specification of conceptual models. It integrates concepts for the modelling of dynamic, structural and process aspects. With the TBench [KHHS95] a specification tool for Troll is ....

....algebraic methods, statements over object states are expressed with a logic calculus, the dynamic structure of the system, i.e. the systems evolution, is reflected via a temporal logic which is interpreted in terms of event structures. An exhaustive description of the model theory is given in [ES95] In the following we intuitively explain these semantic ingredients. Moreover, in Sect. 4 the semantic notions are illustrated by example. Static structures are needed to describe the state of objects. Such static structures are defined by data signatures and their algebraic interpretation. We ....

[Article contains additional citation context not shown here]

H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. In E. Astesiano, G. Reggio, and A. Tarlecki, editors, Recent Trends in Data Types Specification, Proc. 10th Workshop on Specification of Abstract Data Types joint with the 5th COMPASS Workshop, S.Margherita, Italy, May/June

....The focus of our work is the stepwise design and modelling of distributed information systems with object oriented techniques. We put emphasis on the need of a well defined formal background. The basis of our work is the model for distributed families of concurrent objects presented in [ES95] We syntactically introduce transactions into object oriented specification and propose a temporal logic which can speak about transactions to formalize such specifications. Moreover, we give an appropriate interpretation of specifications which incorporate transactions based on event ....

....In this paper, we will introduced transactions into object oriented specifications. Besides proposing language features for the specification language Troll, we will mainly develop a languageindependent theory to treat transactions semantically. Our investigations enlarge the theory given in [ES95] by transactions. In [ES95] a standard semantics for concurrent object societies is provided using event structures. We will illustrate our ideas by example. The rest of the paper is organized as follows. Sect. 2 introduces transactions syntactically. Transactions in Troll specifications are ....

[Article contains additional citation context not shown here]

H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. In E. Astesiano, G. Reggio, and A. Tarlecki, editors, Recent Trends in Data Types Specification, Proc. 10th Workshop on Specification of Abstract Data Types joint with the 5th COMPASS Workshop, S.Margherita, Italy, May/June

....different frames, that is, they may differ in the set of worlds and or in the accessibility relations. An even more interesting alternative is to consider a base institution that may lead to categories of objects with products reflecting full concurrency . Work on this direction is reported in [19] and [12] considering event structures [52, 53] as basic interpretation structures and their associated temporal logics [31, 32, 37] Another possibility would be to consider the temporal logic proposed in [41] Please note that, whichever is the base logic (institution) being considered, for ....

H.-D. Ehrich and A. Sernadas. Local specification of distributed families of sequential objects. In E. Astesiano and G. Reggio, editors, Recent Trends in Data Type Specification, pages 219--235. Springer Verlag, 1995. LNCS 906.

....[DH97] is the first to address problems of concurrency and communication, and to integrate benefits from informal methods like OMT [JWH 94] So there is a graphical notation for Troll3 called omTroll. Theoretical foundations of concurrency as applied to this approach have been explored in [ES95, Ehr97, Kus97] among others. EH96] gives a brief overview of Troll3 and omTroll and their logic foundations. Troll does not only have a formal syntax and semantics, but also a method and a workbench [HDK 97, GK97] The approach is being developed along with a practical project [KKH 96, ....

H.-D. Ehrich and A. Sernadas. Local Specification of Distributed Families of Sequential Objects. In E. Astesiano, G. Reggio, and A. Tarlecki, editors, Recent Trends in Data Types Specification, Proc. 10th ADT Workshop /5th COMPASS Workshop, Selected papers, pages 219--235. Springer, Berlin, LNCS 906, 1995.

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