One must be able to say at all times - in stead of points, straight lines, and planes - tables, chairs and beer mugs. (David Hilbert) One service mathematics has rendered the human race. It has put common sense back where it belongs, on the topmost shelf next to the dusty canister labelled "discarded nonsense. " (Eric T. Bell) This book discusses reasoning with partial information. We investigate the proof theory, the model theory and some applications of reasoning with par tial information. We have as a goal a general theory for combining, in a principled way, logic formulae expressing partial information, and a logical tool for choosing among them for application and implementation purposes. We also would like to have a model theory for reasoning with partial infor mation that is a simple generalization of the usual Tarskian semantics for classical logic. We show the need to go beyond the view of logic as a geometry of static truths, and to see logic, both at the proof-theoretic and at the model-theoretic level, as a dynamics of processes. We see the dynamics of logic processes bear with classical logic, the same relation as the one existing between classical mechanics and Euclidean geometry."

Topics * what this book is about, * its intended audience, * what the reader ought to know, * how the book is organized, * acknowledgements. Specifications express information about a program that is not normally part of the program, and often cannot be expressed in a programming lan guage. In the past, the word "specification" has sometimes been used to refer to somewhat vague documentation written in English. But today it indicates a precise statement, written in a machine processable language, about the purpose and behavior of a program. Specifications are written in languages that are just as precise as programming languages, but have additional capabilities that increase their power of expression. The termi nology formal specification is sometimes used to emphasize the modern meaning. For us, all specifications are formal. The use of specifications as an integral part of a program opens up a whole new area of programming - progmmming with specifications. This book describes how to use specifications in the process of building programs, debugging them, and interfacing them with other programs. It deals with a new trend in programming - the evolution of specification languages from the current generation of programming languages. And it describes new strategies and styles of programming that utilize specifications. The trend is just beginning, and the reader, having finished this book, will viii Preface certainly see that there is much yet to be done and to be discovered about programming with specifications.

This book constitutes the thoroughly refereed post-conference proceedings of the 8th International Workshop on Model-Based Methodologies for Pervasive and Embedded Software, MOMPES 2012, held in Essen, Germany, in September 2012. The 7 revised full papers presented together with 1 short papers were carefully reviewed and selected from 16 submissions. The papers cover a large spectrum of topics including model-driven engineering, model analysis, runtime verification, modeling of reactive systems, variability modeling, and domain-specific languages.

PHP is rapidly becoming the language of choice for dynamic Web development, in particular for e-commerce and on-line database systems. It is open source software and easy to install, and can be used with a variety of operating systems, including Microsoft Windows and UNIX. This comprehensive manual covers the basic core of the language, with lots of practical examples of some of the more recent and useful features available in version 5.0. MySQL database creation and development is also covered, as it is the developer database most commonly used alongside PHP. It will be an invaluable book for professionals wanting to use PHP to develop their own dynamic web pages. Key Topics: - Basic Language Constructs - Manipulating Arrays and Strings - Errors and Buffering - Graphic Manipulation - PDF Library Extension - MySQL Database Management - Classes and Objects Concepts Features and Benefits: Explains how to use PHP to its full extent - covering the latest features and functions of PHP version 5.0, including the use of object-oriented programming Describes how to link a database to a web site, using the MySQL database management system Shows how to connect PHP to other systems and provides many examples, so that you can create powerful and dynamic web pages and applications Contains lots of illustrated, practical, real-world examples - including an e-commerce application created in PHP using many of the features described within the book The scripts used in the examples are available for download from www.phpmysql-manual.com

Massively Parallel Systems (MPSs) with their scalable computation and storage space promises are becoming increasingly important for high-performance computing. The growing acceptance of MPSs in academia is clearly apparent. However, in industrial companies, their usage remains low. The programming of MPSs is still the big obstacle, and solving this software problem is sometimes referred to as one of the most challenging tasks of the 1990's. The 1994 working conference on "Programming Environments for Massively Parallel Systems" was the latest event of the working group WG 10.3 of the International Federation for Information Processing (IFIP) in this field. It succeeded the 1992 conference in Edinburgh on "Programming Environments for Parallel Computing". The research and development work discussed at the conference addresses the entire spectrum of software problems including virtual machines which are less cumbersome to program; more convenient programming models; advanced programming languages, and especially more sophisticated programming tools; but also algorithms and applications.

The representation of uncertainty is a central issue in Artificial Intelligence (AI) and is being addressed in many different ways. Each approach has its proponents, and each has had its detractors. However, there is now an in creasing move towards the belief that an eclectic approach is required to represent and reason under the many facets of uncertainty. We believe that the time is ripe for a wide ranging, yet accessible, survey of the main for malisms. In this book, we offer a broad perspective on uncertainty and approach es to managing uncertainty. Rather than provide a daunting mass of techni cal detail, we have focused on the foundations and intuitions behind the various schools. The aim has been to present in one volume an overview of the major issues and decisions to be made in representing uncertain knowl edge. We identify the central role of managing uncertainty to AI and Expert Systems, and provide a comprehensive introduction to the different aspects of uncertainty. We then describe the rationales, advantages and limitations of the major approaches that have been taken, using illustrative examples. The book ends with a review of the lessons learned and current research di rections in the field. The intended readership will include researchers and practitioners in volved in the design and implementation of Decision Support Systems, Ex pert Systems, other Knowledge-Based Systems and in Cognitive Science."

The need for a comprehensive survey-type exposition on formal languages and related mainstream areas of computer science has been evident for some years. In the early 1970s, when . the book Formal Languages by the second mentioned editor appeared, it was still quite feasible to write a comprehensive book with that title and include also topics of current research interest. This would not be possible anymore. A standard-sized book on formal languages would either have to stay on a fairly low level or else be specialized and restricted to some narrow sector of the field. The setup becomes drastically different in a collection of contributions, where the best authorities in the world join forces, each of them concentrat ing on their own areas of specialization. The present three-volume Handbook constitutes such a unique collection. In these three volumes we present the current state of the art in formal language theory. We were most satisfied with the enthusiastic response given to our request for contributions by specialists representing various subfields. The need for a Handbook of Formal Languages was in many answers expressed in different ways: as an easily accessible his torical reference, a general source of information, an overall course-aid, and a compact collection of material for self-study. We are convinced that the final result will satisfy such various needs. The theory of formal languages constitutes the stem or backbone of the field of science now generally known as theoretical computer science.

Prolog has a declarative style. A predicate definition includes both the input and output parameters, and it allows a programmer to define a desired result without being concerned about the detailed instructions of how it is to be computed. Such a declarative language offers a solution to the software crisis, because it is shorter and more concise, more powerful and understandable than present-day languages. Logic highlights novel aspects of programming, namely using the same program to compute a relation and its inverse, and supporting deductive retrieval of informa tion. This is a book about using Prolog. Its real point is the examples introduced from Chapter 3 onwards, and so a Prolog programmer does not need to read Chapters 1 and 2, which are oriented more to teachers and to students, respec tively. The book is recommended for introductory and advanced university courses, where students may need to remember the basics about logic program ming and Prolog, before starting doing. Chapters 1 and 2 were also kept for the sake of unity of the whole material. In Chapter 1 a teaching strategy is explained based on the key concepts of Pro log which are novel aspects of programming. Prolog is enhanced as a computer programming language used for solving problems that involve objects and the relationships between objects. This chapter provides a pedagogical tour of pre scriptions for the organization of Prolog programs, by pointing out the main draw backs novices may encounter."

Augmented Transition Network Grammars are at present the most widely used method for analyzing natural languages. Despite the increasing po pularity of this method, however, no extensive papers on ATN-Grammars have been presented which would be accessible to a larger number of per sons engaged in the problem from both the theoretical and practical points of view. Augmented Transition Networks (ATN) are derived from state automata. Like a finite state automaton, an ATN consists of a collection of la beled states and arcs, a distinguished start state and a set of distin guished final states. States are connected with each other by arcs crea ting a directed graph or net. The label on an arc indicates a terminal symbol (word) or the type of words which must occur in an input stream to allow the transition to the next state. It is said that a sequence of words (or sentence) is accepted by such a net if there exists a se quence of arcs (usually called a path), connecting the start state with a final state, which can be followed to the sentence. The finite state automaton is then enriched by several facilities which increase its computational power. The most important of them permits some arcs to be labeled by nonterminal rather than terminal symbols. This means that the transition through such an arc is actually the re cursive application of the net beginning with a pointed state."

"I prefer to view formal methods as tools. the use of which might be helpful." E. W. Dijkstra Algebraic specifications are about to be accepted by industry. Many projects in which algebraic specifications have been used as a design tool have been carried out. What prevents algebraic specifications from breaking through is the absence of introductory descriptions and tools supporting the construction of algebraic specifications. On the one hand. interest from industry will stimulate people to make introductions and tools. whereas on the other hand the existence of introductions and tools will stimulate industry to use algebraic specifications. This book should be seen as a contribution towards creating this virtuous circle. The book will be of interest to software designers and programmers. It can also be used as material for an introductory course on algebraic specifications and software engineering at undergraduate or graduate level. Nowadays. there is general agreement that in large software projects appropriate specifications are a must in order to obtain quality software. Informal specifications alone are certainly not appropriate because they are incomplete. inconsistent. inaccurate and ambiguous and they rapidly become bulky and therefore useless. The only way to overcome this problem is to use formal specifications. An important remark here is that a specification formalism (language) alone is not sufficient. What is also needed is a design method to write specifications in that formalism.

This book introduces the tools you'll need to program with the packetC language packetC speedsthe development ofapplications that live within computer networks, the kind of programs that provide network functionality for connecting "clients" and "servers and clouds."The simplest examples provide packet switching and routing while more complex examples implement cyber security, broadband policies or cloud-based network infrastructure. Network applications, such as those processing digital voice and video, must be highly scalable, secure and maintainable. Such application requirements translate to requirements for a network programming language that leverages massively-parallel systems and ensures a high level of security, while representing networking protocols and transactions in the simplest way possible. packetC meets these requirements with an intuitive approach to coarse-grained parallelism, with strong-typing and controlled memory access for security and with new data types and operators that express the classic operations of the network-oriented world in familiar programming terms. No other language has addressed the full breadth of requirements for tractable parallelism, secure processing and usable constructs. The packetC language is growing in adoption and has been used to develop solutions operating in some of the world's largest networks. What you'll learn This book is the primary document specifying the language from a developer's point of view and act as the formal language user's guide. It covers: How to program applications in packetC. The parallel programming model of packetC Deviations from C99 and the unique aspects of packetC How to leverage existing C code and the applicability of the C standard libraries Who this book is for

packetC Programming is written for a widevariety of potential programmers. Most importantly, it's for people who need to use packetC to program for the Internet backbone. Still, knowledge of the packetC language will help a much wider array of programmers who need to write effective code that will be optimized for the cloud and workeffectively and efficiently through complex network structures. Finally, readers will learn about how and why packetC is needed, and to better understand the technologies, standards and issues surrounding the 'net. If you really want to understand this level of programming, this book isa must-have Table of Contents PART 1: packetC Background Chapter 1: Origins of packetC Chapter 2: Introduction to packetC Language Chapter 3: Style Guidelines for packetC Programs Chapter 4: Construction of a packetC Program PART 2: Language Reference Chapter 5: VariablesIdentifiers, Basic Scalar Data Types, and Literals Chapter 6: Data Initialization and Mathematical Expressions Chapter 7: Functions Chapter 8: packetC Data Type Fundamentals Chapter 9: C-Style Data Types Chapter 10: Basic Packet Interaction and Operations Chapter 11: Selection Statements Chapter 12: Loops and Flow Control Chapter 13: Exception Handling Chapter 14: Databases Types and Operations Chapter 15: Search Set Types and Operations Chapter 16: Reference Type and Operations Chapter 17: Lock and Unlock Operators Chapter 18: Packet Information Block and System Packet Operations Chapter 19: Descriptor Type and Operations PART 3: Developing Applications Chapter 20: Control Plane and System Interaction Chapter 21: packetC Pre-Processor Chapter 22: Pragmas and Other Key Compiler Directives Chapter 23: Developing Large Applications in packetC Chapter 24: Construction of a packetC Executable Chapter 25: packetC Standard Networking Descriptors Chapter 26: Developing For Performance Chapter 27: Standard Libraries PART 4: Industry Reprints Appendix A: Reference Tables Appendix B: Open Systems Vendors for packetC Appendix C: Glossary Appendix D: CloudShield Products Supporting packetC

Android development is hot, and many programmers are interested in joining the fun. However, because this technology is based on Java, you should first obtain a solid grasp of the Java language and its foundational APIs to improve your chances of succeeding as an Android app developer. After all, you will be busy learning the architecture of an Android app, the various Android-specific APIs, and Android-specific tools. If you do not already know Java fundamentals, you will probably end up with a massive headache from also having to quickly cram those fundamentals into your knowledge base. Learn Java for Android Development, Second Edition teaches programmers of any skill level the essential Java language and foundational Java API skills that must be learned to improve the programmer's chances of succeeding as an Android app developer. Each of the book's 14 chapters provides an exercise section that gives you the opportunity to reinforce your understanding of the chapter's material. Answers to the book's more than 500 exercises are provided in an appendix. A second appendix provides a significant game-oriented Java application, which you can convert into an Android app. Once you complete this book, you should be ready to dive into beginning Android app development. Maybe, start that journey with Apress' Beginning Android. What you'll learn The Java language: This book provides complete coverage of nearly every pre-Java version 7 language feature (native methods are briefly mentioned but not formally covered). Starting with basic language features (e.g., comments, types, expressions, and statements), you progress to those features related to classes and objects, followed by object-oriented features related to inheritance, polymorphism, and interfaces. You then explore the advanced language features for nested types, packages, static imports, exceptions, assertions, annotations, generics, and enums. Continuing, you investigate strictfp, synchronized, volatile, the enhanced for loop statement, autoboxing/unboxing, and transient fields. Java APIs: In addition to Object and APIs related to exceptions, you explore Math, StrictMath, BigDecimal, BigInteger, String, StringBuffer/StringBuilder, Boolean, Character, Byte, Short, Integer, Long, Float, Double, Number, the Threads API, System, Runtime, Process, the Collections Framework, the Concurrency Utilities, Date, Formatter, Random, Scanner, the ZIP and JAR APIs, File, RandomAccessFile, stream classes, and writer/reader classes, InetAddress, SocketOptions, Socket, ServerSocket, DatagramSocket, MulticastSocket, URL, URLConnection, URLEncoder, URLDecoder, NetWorkInterface, InterfaceAddress, CookieHandler, CookieManager, CookieStore, CookiePolicy, Buffer, ByteBuffer, CharBuffer, DoubleBuffer, FloatBuffer, IntBuffer, LongBuffer, ShortBuffer, MappedByteBuffer, Channel, WritableByteChannel, ReadableByteChannel, ScatteringByteChannel, GatheringByteChannel, FileChannel, the Regular Expressions API, JDBC, and more. Applying these: You will learn how to use the JDK's javac (compiler), java (application launcher), javadoc (Java documentation generator), and jar (Java archive creator, updater, and extractor) tools. You will also receive an introduction to the Eclipse integrated development environment, which is the official standard for developing Android apps. Who this book is for

This book is for any programmer - including existing Java programmers and Objective-C-based iPhone and iPad programmers - of any skill level who needs to obtain a solid understanding of the Java language and foundational Java APIs before jumping into Android app development. Table of Contents 1. Getting Started with Java 2. Learning Language Fundamentals 3. Discovering Classes and Objects 4. Discovering Inheritance, Polymorphism, and Interfaces 5. Mastering Advanced Language Features Part 1 6. Mastering Advanced Language Features Part 2 7. Exploring the Basic APIs Part 1 8. Exploring the Basic APIs Part 2 9. Exploring the Collections Framework 10. Exploring Additional Utility APIs 11. Performing Classic I/O 12. Accessing Networks 13. Migrating to New I/O 14. Accessing Databases A. Appendix A: Solutions to Exercises B. Appendix B: Four of a Kind C. Appendix C: Odds and Ends***

Once programmers have grasped the basics of object-oriented programming and C++, the most important tool that they have at their disposal is the Standard Template Library (STL). This provides them with a library of re-usable objects and standard data structures. It has recently been accepted by the C++ Standards Committee. This textbook is an introduction to data structures and the STL. It provides a carefully integrated discussion of general data structures and their implementation and use in the STL. In so doing, the author is able to teach readers the important features of abstraction and how to develop applications using the STL.

This book is a detailed account of the Synthesizer Generator, a system for creat ing specialized editors that are customized for editing particular languages. The book is intended for those with an interest in software tools and in methods for building interactive systems. It is a must for people who are using the Syn thesizer Generator to build editors because it provides extensive discussions of how to write editor specifications. The book should also be valuable for people who are building specialized editors "by hand," without using an editor generating tool. The need to manage the development of large software systems is one of the most pressing problems faced by computer programmers. An important aspect of this problem is the design of new tools to aid interactive program develop ment. The Synthesizer Generator permits one to create specialized editors that are tailored for editing a particular language. In program editors built with the Synthesizer Generator, knowledge about the language is used to continuously assess whether a program contains errors and to determine where such errors occur. The information is then displayed on the terminal screen to provide feed back to the programmer as the program is developed and modified."

This book is an anthology of the results of research and development in database query processing during the past decade. The relational model of data provided tremendous impetus for research into query processing. Since a relational query does not specify access paths to the stored data, the database management system (DBMS) must provide an intelligent query-processing subsystem which will evaluate a number of potentially efficient strategies for processing the query and select the one that optimizes a given performance measure. The degree of sophistication of this subsystem, often called the optimizer, critically affects the performance of the DBMS. Research into query processing thus started has taken off in several directions during the past decade. The emergence of research into distributed databases has enormously complicated the tasks of the optimizer. In a distributed environment, the database may be partitioned into horizontal or vertical fragments of relations. Replicas of the fragments may be stored in different sites of a network and even migrate to other sites. The measure of performance of a query in a distributed system must include the communication cost between sites. To minimize communication costs for-queries involving multiple relations across multiple sites, optimizers may also have to consider semi-join techniques.

This book constitutes the proceedings of the 16th International Conference on Fundamental Approaches to Software Engineering, FASE 2013, held as part of the European Joint Conference on Theory and Practice of Software, ETAPS 2013, which took place in Rome, Italy, in March 2013. The 25 papers presented in this volume were carefully reviewed and selected from 112 submissions. They are organized in topical sections named: model-driven engineering; verification and validation; software comprehension; analysis tools; model-driven engineering: applications; model transformations; and testing.

The success of VHDL since it has been balloted in 1987 as an IEEE standard may look incomprehensible to the large population of hardware designers, who had never heared of Hardware Description Languages before (for at least 90% of them), as well as to the few hundreds of specialists who had been working on these languages for a long time (25 years for some of them). Until 1988, only a very small subset of designers, in a few large companies, were used to describe their designs using a proprietary HDL, or sometimes a HDL inherited from a University when some software environment happened to be developped around it, allowing usability by third parties. A number of benefits were definitely recognized to this practice, such as functional verification of a specification through simulation, first performance evaluation of a tentative design, and sometimes automatic microprogram generation or even automatic high level synthesis. As there was apparently no market for HDL's, the ECAD vendors did not care about them, start-up companies were seldom able to survive in this area, and large users of proprietary tools were spending more and more people and money just to maintain their internal system.

This book comprises selected papers of the International Conferences, ASEA, DRBC and EL 2011, held as Part of the Future Generation Information Technology Conference, FGIT 2011, in Conjunction with GDC 2011, Jeju Island, Korea, in December 2011. The papers presented were carefully reviewed and selected from numerous submissions and focuse on the various aspects of advances in software engineering and its Application, disaster recovery and business continuity, education and learning.

The advent of the world-wide web and web-based applications have dramatically changed the nature of computer applications. Computer system design, in the light of these changes, involves understanding these modem workloads, identifying bottlenecks during their execution, and appropriately tailoring microprocessors, memory systems, and the overall system to minimize bottlenecks. This book contains ten chapters dealing with several contemporary programming paradigms including Java, web server and database workloads. The first two chapters concentrate on Java. While Barisone et al.'s characterization in Chapter 1 deals with instruction set usage of Java applications, Kim et al.'s analysis in Chapter 2 focuses on memory referencing behavior of Java workloads. Several applications including the SPECjvm98 suite are studied using interpreter and Just-In-Time (TIT) compilers. Barisone et al.'s work includes an analytical model to compute the utilization of various functional units. Kim et al. present information on locality, live-range of objects, object lifetime distribution, etc. Studying database workloads has been a challenge to research groups, due to the difficulty in accessing standard benchmarks. Configuring hardware and software for database benchmarks such as those from the Transactions Processing Council (TPC) requires extensive effort. In Chapter 3, Keeton and Patterson present a simplified workload (microbenchmark) that approximates the characteristics of complex standardized benchmarks.

Parallel Language and Compiler Research in Japan offers the international community an opportunity to learn in-depth about key Japanese research efforts in the particular software domains of parallel programming and parallelizing compilers. These are important topics that strongly bear on the effectiveness and affordability of high performance computing systems. The chapters of this book convey a comprehensive and current depiction of leading edge research efforts in Japan that focus on parallel software design, development, and optimization that could be obtained only through direct and personal interaction with the researchers themselves.

The aim of this book is to present fundamentals of algebraic specifications with respect to the following three aspects: fundamentals in the sense of a carefully motivated introduction to algebraic specifications, which is easy to understand for computer scientists and mathematicians; fundamentals in the sense of mathematical theories which are the basis for precise definitions, constructions, results, and correctness proofs; and fundamentals in the sense of concepts, which are introduced on a conceptual level and formalized in mathematical terms. The book is equally suitableas a text book for graduate courses and as a reference for researchers and system developers.

Combinatory logic started as a programme in the foundation of mathematics and in an historical context at a time when such endeavours attracted the most gifted among the mathematicians. This small volume arose under quite differ ent circumstances, namely within the context of reworking the mathematical foundations of computer science. I have been very lucky in finding gifted students who agreed to work with me and chose, for their Ph. D. theses, subjects that arose from my own attempts 1 to create a coherent mathematical view of these foundations. The result of this collaborative work is presented here in the hope that it does justice to the individual contributor and that the reader has a chance of judging the work as a whole. E. Engeler ETH Zurich, April 1994 lCollected in Chapter III, An Algebraization of Algorithmics, in Algorithmic Properties of Structures, Selected Papers of Erwin Engeler, World Scientific PubJ. Co., Singapore, 1993, pp. 183-257. I Historical and Philosophical Background Erwin Engeler In the fall of 1928 a young American turned up at the Mathematical Institute of Gottingen, a mecca of mathematicians at the time; he was a young man with a dream and his name was H. B. Curry. He felt that he had the tools in hand with which to solve the problem of foundations of mathematics mice and for all. His was an approach that came to be called "formalist" and embodied that later became known as Combinatory Logic."

This book constitutes the thoroughly refereed post-conference proceedings of the 15th International SDL Forum, SDL 2011, held in Toulouse, France, in July 2011. The 16 revised full papers presented together were carefully reviewed and selected for inclusion in the book. The papers cover a wide range of topics such as SDL and related languages; testing; and services and components to a wide range presentations of domain specific languages and applications, going from use maps to train station models or user interfaces for scientific dataset editors for high performance computing.

One service mathematics has rendered the tEL moi, .... si j'avait su comment en revenir. je n'y serais point alle'.' human race. It has put common sense back Jules Verne where it belongs, on the topmost shelf next to the dusty canister labelled 'discarded non sense', The series is divergent; therefore we may be Eric T. Bell able to do something with it. O. Heaviside Mathematics is a tool for thought. A highly necessary tool in a world where both feedback and non linearities abound. Similarly, all kinds of parts of mathematics serve as tools for other parts and for other sciences. Applying a simple rewriting rule to the quote on the right above one finds such statements as: 'One service topology has rendered mathematical physics ...'; 'One service logic has rendered com puter science ...'; 'One service category theory has rendered mathematics, ..'. All arguably true. And all statements obtainable this way form part of the raison d'elre of this series."

At present one of the main obstacles to a broader application of expert systems is the lack of a theory to tell us which problem-solving methods areavailable for a given problem class. Such a theory could lead to significant progress in the following central aims of the expert system technique: - Evaluating the technical feasibility of expert system projects: This depends on whether there is a suitable problem-solving method, and if possible a corresponding tool, for the given problem class. - Simplifying knowledge acquisition and maintenance: The problem-solving methods provide direct assistance as interpretation models in knowledge acquisition. Also, they make possible the development of problem-specific expert system tools with graphical knowledge acquisition components, which can be used even by experts without programming experience. - Making use of expert systems as a knowledge medium: The structured knowledge in expert systems can be used not only for problem solving but also for knowledge communication and tutorial purposes. With such a theory in mind, this book provides a systematic introduction to expert systems. It describes the basic knowledge representations and the present situation with regard tothe identification, realization, and integration of problem-solving methods for the main problem classes of expert systems: classification (diagnostics), construction, and simulation.