-
[show abstract]
[hide abstract]
ABSTRACT: The InterACT tool is a theorem prover for algebraic specifications with conditional equations emphasizing user-friendliness and interaction. Its purpose is mainly educational, e.g. to support the teaching of formal methods. It already has been used successfully in universitary courses on formal specification of software systems. InterACT provides a graphical user interface that supports proving by mouse.
04/2006: pages 563-566;
-
[show abstract]
[hide abstract]
ABSTRACT: The InterACT tool is an interactive theorem prover for algebraic specifications emphasizing user-friendliness. InterACT is integrated in the existing ACT environment. The main purpose of InterACT is to teach formal methods in universitary courses about formal specification of software systems. It has already been used successfully in this area.
The theoretical and practical concepts underlying InterACT are described in this paper. Ideas for the design of user interfaces for interactive theorem provers can be found.
01/2006: pages 291-305;
-
[show abstract]
[hide abstract]
ABSTRACT: We describe how Z can be combined with dynamic modelling techniques such as Statecharts and temporal interval logic. The presented formalism, SZ, integrates Z's power to describe data and data-transformation with techniques and an adequate semantic model for reactive systems. SZ also defines powerful means of structuring a specification. The formalism is introduced in presenting parts of the specification of an intelligent cruise control.
09/2001;
-
Bulletin of the EATCS. 01/2000; 70:77-81.
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper we present an approach for the definition of object-oriented modeling languages using a metamodel. In order to achieve a precise semantics we are using the formal specification language Object-Z as a metalanguage. We are considering abstract syntax and static semantics in order to define the concepts of models and the constraints between different models. The behavior of the models is determined by its dynamic semantics. Especially for behavioral models like statecharts or interaction diagrams, the dynamic semantics is very important. Using Object-Z we have one single metalanguage defined independently from the UML for all three aspects (abstract syntax, static semantics and dynamic semantics). Using this approach we define object-oriented statecharts as proposed by Harel and Gery [12] and used in the UML. Object-oriented statecharts are used for the specification of the complete behavior of classes. The abstract syntax and the static semantics define the structure of sta...
10/1999;
-
[show abstract]
[hide abstract]
ABSTRACT: This is the reference manual for the #SZ speci#cation notation. #SZ is a combination of statecharts and Z for the speci#cation of safety-critical control systems. It combines statecharts ' expressivepower for the description of reactive behavior with Z's ability to describe data and data transformation. Additionally, Z is extended for the speci#cation of abstract temporal properties and means to structure the speci#cation in components are introduced. This manual covers a complete presentation of the language, including its visible syntax, a #rst glance at a #SZ library, the L A T E X input syntax, and support for Statemate speci#cations. Contents 1 Introduction 2 2 Top-Level Objects 3 3 Specifying the Data Space 5 4 Specifying Operational Behavior 8 5 Specifying Behavioral Constraints 14 6 Specifying Structural Embedding 18 AL A T E X Syntax for #SZ 20 BL A T E X Symbols 25 C Library 27 D Alternative External Representations 29 E Using Statemate 30 1 1. Introduction 1 I...
10/1999;
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper weintroduce a formal approach for the specification of safety-critical embedded systems. The specification formalisms Z and statecharts are integrated under a suitable structural model. The combined approach uses the advantages of the formalisms while avoiding their disadvantages. The different formalisms yield different, compatible views on the system: the functional view describing data and data-transformation, the reactive view, describing the system's reaction upon external stimuli, and the structural view, describing the components of the system and their interaction. The combination is discussed presenting parts of a case study: a traffic light control system. The case study is oriented at original planning documents. Besides its safety- and real-time-aspects, the case study is particularly interesting because structuring and reuse is of considerable importance in this example.
10/1999;
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper we present an algebraic approach to statecharts as they are used in the Statemate tool in the style of "Petri-Nets are Monoids" for place-transition nets developed by Meseguer and Montanari. We apply the framework of high-level-replacement systems, a categorical generalization of graph transformation systems, in order to de#ne union as horizontal as well as transformation and re#nementasvertical structuring techniques for statecharts. The #rst main result shows compatibility of union and transformation in a suitable category of statecharts. We present an algorithm for the computation of all transitions enabled within one step. The second main result shows the correctness of this algorithm. We de#ne re#nement morphisms for statecharts, which allow re#nement of arbitrary states, in contrast to concepts in the literature where only basic and root states are subject of re#nement. The third main result shows that re#nement morphisms are compatible with the behavio...
10/1999;
-
[show abstract]
[hide abstract]
ABSTRACT: Syntax : An abstract description of the entities that form a model of the respective language. ffl Static Semantics (context conditions, constraints) : Well-formedness conditions between the syntactic entities, such as absence of circular inheritance. ffl Dynamic Semantics (denotation): The (operational) behavior of the entities of the specification, such as I/O, reaction to stimuli, effect of executing an operation, etc. Especially the description of dynamic semantics in a metamodel is not treated in a precise way in other approaches. The dimensions of metamodeling are depicted in Figure 1. The concepts of intensional and extensional entities and its relation to abstract syntax, static and dynamic semantics are summarized in Table 1. Intensional Entities Extensional Entities abstract Syntax static Semantics Figure 1: The Dimensions of Metamodeling A metaentity has an internal state that is protected by object-oriented encapsulation principles. This ensures that each metaentity has ...
02/1999;
-
Herbert Weber, Marcus Klar,
Stefan Mann,
Ralf-Detlef Kutsche,
Stefan Jähnichen,
Robert Büssow,
Hartmut Ehrig,
Robert Geisler,
Gabriel Baum,
Claudia Pons,
Miguel Felder,
Sergio Waldoke
01/1999
-
[show abstract]
[hide abstract]
ABSTRACT: ion A metamodel is a model for the information that can be expressed during (software) modeling. Basically, a metamodel is a model of models. It consists of entities defining the model elements and therefore the modeling language. The main purpose of a metamodel is to relate these model elements. The different levels of abstraction are illustrated in Fig. 2 [Ode95]. On the data- and process-level, the entities are run-time objects, i.e. instances of classes and processes running on a concrete system. On the level of models, we have different models describing the underlying physical system, e.g. Employee and Employer are classes of a structure diagram. The next abstraction, the metamodel level, describes the model in which, for example, the entities are classes and objects. Following the example given in Fig. 2, we consider Employer as an instance of Class of the metamodel. In order to express these concepts, we need a further level, defining the used language for the metamodel. This...
06/1998;
-
Inform., Forsch. Entwickl. 01/1998; 13:43-46.
-
01/1998
-
[show abstract]
[hide abstract]
ABSTRACT: InterACT [GK95, KGC95, GKC96] is an interactive theorem and completeness prover for algebraic specifications. A specification of a safety critical system, a hydraulic press, is developed and interesting safety properties of the system are proved using the InterACT- tool. Contents 1 Problem Description 1 2 The Specification 4 3 Theorems, Proofs and Conclusion 11 3.1 Characteristics of the Press . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2 State Transitions of the Press . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.3 Safety Conditions of the Press . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Starting point for this case study was a diploma thesis [Lat95] in which a control system of a hydraulic press was developed using the specification Language Z [Spi89]. In this thesis, no formal proofs were given. The hydraulic press is a real time system with sa...
07/1996;
-
02/1996;
-
Algebraic Methodology and Software Technology, 5th International Conference, AMAST '96, Munich, Germany, July 1-5, 1996, Proceedings; 01/1996
-
Recent Trends in Data Type Specification, 11th Workshop on Specification of Abstract Data Types Joint with the 8th COMPASS Workshop, Oslo, Norway, September 19-23, 1995, Selected Papers; 01/1995
-
01/1993;
