ISO-IS-8807. Information processing systems, open systems interconnection, LOTOS, a formal description technique based on the temporal ordering of observational behaviour, 1989.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....isEmpty(q) false, priority(get(q) lt priority(m) remove(add(m,q) q; definition of isEmpty isEmpty(emptyq) true; isEmpty(add(m,q) false; definition of priority priority( n,s) n; definition of text text( n,s) s; endtype Figure 2. The PriorityQueue type in LOTOS [11] 1. gates 2. in: inGate,ready 3. out: outGate 4. behavior 5. Buffer(emptyq) Initial state 7. process Buffer(Q:Queue) Parameterized process 8. inGate M:Message;Buffer(add(M,Q) 9. or operator 10. ready ;BufferReady(Q) 13. process BufferReady(Q:Queue) 14. ....

ISO. LOTOS, a formal description technique based on the temporal ordering of observational behaviour. Technical Report 8807, 1989.

....tool . 38 3.7 Execution example . 40 4 Conclusions and future work 41 A ACT ONE and LOTOS signatures 43 1 Introduction The formal description technique LOTOS [11] was developed within ISO for the formal speci cation of open distributed systems. Its behaviour description part is based on process algebras, borrowing ideas from CCS [15] and CSP [10] and the mechanism to de ne and to deal with data types is based on ACT ONE [8] LOTOS became an ....

....within ISO for the formal speci cation of open distributed systems. Its behaviour description part is based on process algebras, borrowing ideas from CCS [15] and CSP [10] and the mechanism to de ne and to deal with data types is based on ACT ONE [8] LOTOS became an international standard (IS 8807) in 1989. Since its standardization, LOTOS has been used to describe hundreds of systems, and most of this success is due to the existence of tools where speci cations can be executed, compared, and analyzed. The standard de nes LOTOS semantics by means of labelled transition systems, where each data ....

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ISO/IEC. LOTOS|A formal description technique based on the temporal ordering of observational behaviour. International Standard 8807, International Organization for standardization | Information Processing Systems | Open Systems Interconnection, Geneva, Sept. 1989.

....considered to be entities with an unlimited life span. Instead, the life span of a process is restricted by hard timing constraints. In some sense, this allows for more accurate representations of real life systems. Process algebras come in various variants, such as CCS [23] CSP [18] Lotos [7, 1] or ACP [5] The process algebra employed in this paper is CRL t [11] and a minor extension thereof, called t . In this paper, we will restrict ourselves to presenting the syntax of CRL t and CRL t , and its operational semantics. The axioms are included in appendix A. 4.1 Data Types ....

ISO/IEC 8807. A Formal Description Technique Based on the Temporal Ordering of Observational Behaviour, 1988.

....unambiguous speci cation of dynamic behaviour; 2. The formalism should be supported by tools able to analyse, validate and verify descriptions in this formalism. Even though a number of formalisms adhere to these requirements, a slight preference for a process algebraic formalism led to Lotos [8, 2]. The tool support used in this project for Lotos consists of the tool sets Lite [12] and Eucalyptus [14, 13] various 1998 beta versions of CADP 97b Li ege ) Managed Object Managed Object OM protocol entity OM protocol entity RR service provider Provider OM RR Service RR SAP OM SAP Fig. ....

ISO/IEC 8807. Information Processing Systems, Open Systems Interconnection, LOTOS { A Formal Description Technique Based on the Temporal Ordering of Observational Behaviour. Geneva, 1989.

....is a hot topic. These relatively recent developments provide a new area of application for process algebras, having a history of being applied to discrete systems, such as (data) communications protocols. Within the theory of process algebras, various approaches exist, such as CCS [19] Lotos [15] and ACP [3] Already a few case studies, in which process algebras have been used to describe a hybrid system, have been made (e.g. 1] and [11] In this article, the formalism timed CRL [9] is used to describe and analyse a hybrid system, consisting of a conveyor belt and its controller. The ....

ISO/IEC. A Formal Description Technique Based on the Temporal Ordering of Observational Behaviour. ISO, 1988.

....The analysis of these different aspects of communication protocols is usually done according to the following techniques: formal modeling , to verify some properties of the protocol. This requires to model the protocol behavior according to some formal description language, such as LOTOS [ISO88], and to run some formal verification tool. Description languages are nowadays powerful enough to capture most of the protocol semantics, however, verification tools are often quite limited in the size and complexity of the descriptions they can deal with. Some important aspects of a network ....

ISO - Information Processing Systems - Open Systems Interconnection - LOTOS, A Formal Description Technique Based on the Temporal Ordering of Observational Behaviour. IS 8807, 1988.

....most of the interactions which we studied correspond 2 to incomplete and informal requirements models. In other words, if the features were modelled better then we would be able to better understand what is and what isn t an interaction. LOTOS (Language Of Temporal Ordering Speci cations) see [40, 28], is a wide spectrum language, which is suitable for specifying systems at various levels of abstraction. Consequently, it can be used at both ends of the software development spectrum. Its natural division into ADT part (based on ACT ONE [16] and process algebra part (similar to CSP [26] and CCS ....

ISO. LOTOS | a formal description technique based on the temporal ordering of observed behaviour. Technical report, International Organisation for Standardisation IS 8807, 1988. 24

....establish that recon guration preserves the consistency of the application. Starting from the informal description of the protocol given in [PBR99] and a Java implementation that was already in use, we produced a formal speci cation of the protocol using the Iso Formal Description Technique Lotos [ISO88] We then identi ed a set of safety and liveness properties characterizing the desired behaviour of each recon guration primitive of the protocol. To verify whether these correctness properties hold for the Lotos speci cation, we used the model checking approach [CGP00] veri cation was carried ....

....3 Formal speci cation In this section we give a brief overview of Lotos and then we detail the speci cation of the dynamic recon guration protocol. RR n 4222 8 M. Aguilar Cornejo, H. Garavel, R. Mateescu, N. de Palma 3. 1 Overview of LOTOS Lotos (Language Of Temporal Ordering Speci cation) ISO88] is a Formal Description Technique standardized by Iso for specifying communication protocols and distributed systems. Its design was motivated by the need for a language with a high abstraction level and strong mathematical basis, which could be used for the description and analysis of complex ....

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ISO/IEC. LOTOS | A Formal Description Technique Based on the Temporal Ordering of Observational Behaviour. International Standard 8807, International Organization for Standardization | Information Processing Systems | Open Systems Interconnection, Geneve, September 1988.

....prouver des invariants d ex ecution, des propri et es de bon fonctionnement ou de vivacit e. De plus elle est facilement transposable dans un langage informatique. De telles m ethodes de sp ecification existent d ej a. Sans etre exhaustif, on peut citer : ffl les m ethodes alg ebriques Lotos [ISO87a] Estelle [ISO87b] VDM [Jon86] CSP [Hoa85] CCS [Mil80] B [Abr95] ffl les m ethodes bas ees sur la logique temporelle TLA [Lam94] TSOM [Ara93] N eanmoins, a notre connaissance, aucune de ces approches n adresse de facon satisfaisante les probl emes sp ecifiques a l algorithmique ....

ISO 8807. LOTOS, A Formal Description Technique Based on the Temporal Ordering of Observational Behaviour, 1987.

....to the change of the trace distance used in test selection. We have started work on implementing our techniques in the TorX tool environment ( 3] An assumption for implementing our work is that a label distance exists. Because the TorX tools support the input of nite automata de ned in LOTOS [7], we could use a label distance on LOTOS labels. This is not trivial because LOTOS labels may be parameterized by arbitrary data types. ....

ISO. Information Processing Systems, Open Systems Interconnection, LOTOS { A Formal Description Technique Based on the Temporal Ordering of Observational Behaviour. International Standard IS{8807, 1989.

.... operators of most process algebras, for which bisimulation is a congruence (see [YY91] for a discussion on this issue) Although this simple form of compositional veri cation has been applied successfully to some complex systems (e.g. FGM 92, CGM 96] in the case of the Lotos language [ISO88] it may be counter productive in some other cases: generating the Lts of each process separately may lead to state explosion, whereas the generation of the whole system of concurrent processes might succeed if processes constrain each other when composed in parallel. This issue has been ....

....directions for future work. Finally, Appendices A and B illustrate the bene ts of Svl on practical examples. 2 De nitions Labelled Transition Systems are the natural model for action based speci cation languages, especially process algebras such as Ccs [Mil89] Csp [Hoa85] Acp [BK84] or Lotos [ISO88] Formally, an Lts is a tuple M = S; A; T ; s 0 ) where S is the set of states, A the set of actions (or labels) T S A S the transition relation, and s 0 2 S the initial state. A transition (s; a; s 0 ) 2 T indicates that the system can evolve from state s to state s 0 by performing ....

ISO/IEC. LOTOS | A Formal Description Technique Based on the Temporal Ordering of Observational Behaviour. International Standard 8807, International Organization for Standardization | Information Processing Systems | Open Systems Interconnection, Geneve, September 1988.

....in Section 4. We will also point out that it is possible to tune a protocol in order to obtain new properties and improve its behaviour. Finally, we compare our approach with related work. 2. LOTOS specification In our approach the formal specification of a security protocol is written in LOTOS [4,18] which is a standardized language suitable for the description of distributed systems. It is made up of two components: A process algebra, mostly inspired by CCS [29] and CSP [17] with a structured operational semantics. It describes the behaviour of processes and their interactions. LOTOS ....

ISO/IEC: Information Processing Systems-Open Systems Interconnection, LOTOS, a formal description technique based on the temporal ordering of observational behaviour, IS 8807, February 1989.

....a tolerable compromise when evaluating a central rule set. A collection of expert systems introduces inter agent temporal dependencies. A number of approaches to modeling the dependencies between parallel processes may be found in the distributed computing literature (Hoare s CSP [Hoa85] LOTOS [ISO88]) Essentially, agents need to 6 check point at predefined points in their respective execution strategies, typically at points where information exchange is necessary. It is inevitable that certain agents will compute results faster than others due to such factors as rule set size, ....

ISO. LOTOS, A Formal Description Technique based on the Temporal Ordering of Observation Behaviour, 1988. ISO IS 8807.

....of large systems. 3.1.4. 3 Specifying Concurrency The main research in defining formal languages for specifying the behaviour of concurrent and distributed systems includes temporal logic, Lamport s transition axiom [Lam89] and process algebras (for example, CSP [Hoa78] CCS [Mil80] and LOTOS [ISO89]) 58 Temporal logic is a modal logic language for specifying properties of concurrent and distributed systems [Win90] The specification uses operators to refer to the past, current and future states (or events) Lamport s approach combines an axiomatic method for describing the behaviour of ....

....with two formal notations. In DDA, an object oriented model is developed and then formalised in Prolog, resulting in an executable formal model. ROOA consists of defining an object model, refining it and specifying a formal LOTOS OOA model. The object dynamic behaviour is specified by a LOTOS [ISO89] process and its state is specified by Abstract Data Types. DDA s use of Prolog, and ROOA s use of LOTOS while arguably beneficial for user validation of requirements, nevertheless, constrain the abstractness of the specification by introducing execution specific considerations at an early stage ....

ISO, Information Processing Systems. Open Systems Interconnection - LOTOS, A Formal Description Technique Based on the Temporal Ordering of Observational Behaviour. International Standard ISO 8807, 1989.

....in depth. Two examples are provided to illustrate the use of TLOTOS. 1. Introduction In recent years, many quantitative timed extensions of well known asynchronous process algebras have been proposed, as well as new timed process algebras. CSP [Hoa 85] CCS [Mil 89] ACP [BeK 85] LOTOS [ISO 8807] have been extended to Timed CSP [ReR 88, Ree 90] TCCS (Temporal CCS) MoT 89] TIC [QAF 89] ACP r [BaB 90] CELOTOS [HTZ 90] ACP t te [Gro 90] Timed Interaction LOTOS [BLT 90, BoL 91] Timed CCS [Wan 90, Wan 91] and TPCCS [HaJ 90, Han 91] New process algebras have been proposed which are ....

....entity of the well known alternating bit protocol. The second one is a unidirectional medium which introduces delays on the exchanged messages. 2. Upward compatibility with LOTOS The main objective of this timed extension that we are looking for is its upward compatibility with current LOTOS [ISO 8807] This means that, in TLOTOS, a behaviour expression which does not use any language extension should have the same semantics as in standard LOTOS. This allows the description in TLOTOS of untimed behaviours, exactly in the same way as in LOTOS. This requirement is necessary to achieve upward ....

ISO/IEC-JTC1/SC21/WG1/FDT/C, IPS - OSI - LOTOS, a Formal Description Technique Based on the Temporal Ordering of Observational Behaviour, IS 8807, February 1989.

....of LOTOS for guarded processes, and is the basis of the timed extension of LOTOS currently developed by ISO [ISO98] To our knowledge, this is the first in depth study of a language that combines data types and real time behaviours. 1. Introduction The formal description technique LOTOS [BoB87, ISO8807] is an expressive specification language for concurrent and distributed systems. The flexibility of its operators generally allows clear and intuitive descriptions in various specification styles. However, the use of LOTOS has also revealed, or confirmed, some weak points of the language, and ....

ISO#IEC-JTC1#SC21#WG1#FDT#C. LOTOS, a Formal Description Technique Based on the Temporal Ordering of Obser#ational Beha#iour. IS 8807, Feb. 1989.

....of LOTOS for guarded processes, and is the basis of the timed extension of LOTOS currently developed by ISO [ISO98] To our knowledge, this is the first in depth study of a language that combines data types and real time behaviours. 1. Introduction The formal description technique LOTOS [BoB87, ISO89] is an expressive specification language for concurrent and distributed systems. The flexibility of its operators generally allows clear and intuitive descriptions in various specification styles. However, the use of LOTOS has also revealed, or confirmed, some weak points of the language, and ....

ISO#IEC-JTC1#SC21#WG1#FDT#C: LOTOS, a Formal Description Technique Based on the Temporal Ordering of Obser#ational Beha#iour. IS 8807, Feb. 1989.

....that explains how their speci cations can be executed [10] A combination of speci cation languages could be considered, e.g. Z [37] CCS [25] and CSP [14] However, it would be most desirable to use just one speci cation language to provide the required formalism. In this paper, a LOTOS [3, 16] approach for specifying the semantics of UML is presented. LOTOS is a speci cation language that has succeeded in the challenging task of describing structural and 1 behavioural aspects of software systems using a single notation. Indeed, LOTOS has incorporated the speci cation facilities of CCS ....

....models, e.g. class diagrams, and behavioural models, e.g. activity diagrams without object ows. The reading of this paper may ow in a straightforward way for readers that have familiarity with (i) the speci cation of the UML metamodel as described in [27] and (ii) the LOTOS notation [16]. An introductory section on the LOTOS notation along with some explanations concerning the UML metamodel presented throughout the paper try to overcome the requirements (i) and (ii) above. Thus, this paper is structured as follows. Section 2 presents an insight about the current work on ....

ISO/IEC-JTC1/SC21/WG1/FDT/C. LOTOS, a Formal Description Technique Based on the Temporal Ordering of Observational Behaviour, February 1989. IS 8807.

....list disjoint union . 71 18.5 Tuple variable list . 71 19 Further work 71 1 Introduction The ISO formal language LOTOS [1, 6] is composed of a process algebra part (based on CCS [10] and CSP [4] to describe behaviours, and an algebraic language (ACT ONE [3] to describe the abstract data types. This language is mathematically well defined and expressive: it allows the description of concurrency, nondeterminism, ....

ISO. LOTOS, a Formal Description Technique Based on the Temporal Ordering of Observational Behaviour, 1989. IS 8807.

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ISO-IS-8807. Information processing systems, open systems interconnection, LOTOS, a formal description technique based on the temporal ordering of observational behaviour, 1989.

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ISO. LOTOS, a formal description technique based on the temporal ordering of observational behaviour. ISO International Standard 8807, February 1989.

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ISO. LOTOS, a formal description technique based on the temporal ordering of observational behaviour. ISO International Standard 8807, February1ffrua

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ISO. LOTOS, a formal description technique based on the temporal ordering of observational behaviour. ISO International Standard 8807, February 1989.

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ISO TC97#SC21. LOTOS # A Formal Description Technique Based on the Temporal Ordering of Observational Behaviour, 1988. Intl. Standard 8807.

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ISO/IEC-JTC1/SC21/WG1/FDT/C, IPS - OSI - LOTOS, a Formal Description Technique Based on the Temporal Ordering of Observational Behaviour, IS 8807, February 1989.

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