This paper makes two contributions. First, we give a semantics for sets of clauses of the syntactic form L 0 ⇍ L 1 &⋯& L n where each L i is a literal. We call such clauses generally Horn clauses. Any such end...
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This paper makes two contributions. First, we give a semantics for sets of clauses of the syntactic form L 0 ⇍ L 1 &⋯& L n where each L i is a literal. We call such clauses generally Horn clauses. Any such endeavour has to give a coherent, formal treatment of inconsistency (in the sense of two-valued logic). Thus, as a second contribution, we give a robust semantics for generally Horn programs that allows us to “make sense” of sets of generally Horn clauses that are inconsistent (in the two-valued logic sense). This applies to the design of very large knowledge bases where inconsistent information is often present.
Networks of communicating processes can be viewed as networks of stream transformers and programmed in a lazy functional language. Thus the correctness of concurrent systems can be reduced to the correctness of functi...
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This paper is about specification and verification of processes, modelled as CCS-agents. We show, by means of examples that Hennessy-Milner Logic (HML) with recursion is a suitable language for expressing implicit or ...
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We present a method for computing the number of steps needed to compute a lazy first order functional program e (to an approximation of its value). The method itself is described as a lazy functional program. Moreover...
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ISBN:
(纸本)0897913280
We present a method for computing the number of steps needed to compute a lazy first order functional program e (to an approximation of its value). The method itself is described as a lazy functional program. Moreover, it is compositional, because it is denned by recursion on the structure of e. In other words, the number of steps needed to compute e is described in terms of the number of steps the parts of e need. (This is in contrast with the obvious operational method to define an interpreter and count the number of steps that it needs.) The equations that define the analysing program can also be used when reasoning about time complexity of lazy functional programs. Two simple examples are given at the end of the paper.
A method is proposed to search for an identifier by using its type as a key. This can be seen as an approximation of using the specification as a key. Functions that only differ in their currying or argument order are...
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In this paper, we combine the hidden step η of the authors’ paper [2] with the empty process ε of VRANCKEN [12] and the authors’ [3]. We formulate a system ACPc, which is a conservative extension of the systems AC...
In this paper, we combine the hidden step η of the authors’ paper [2] with the empty process ε of VRANCKEN [12] and the authors’ [3]. We formulate a system ACPc, which is a conservative extension of the systems ACPη, ACP√, but also of ACPτ. This is a general system, in which most relevant issues can be discussed. Abstraction from internal steps can be achieved in two ways, in two stages: we can abstract to the hidden step η, and then from η to Milner’s silent step τ.
An LR-based parser generator for arbitrary context-free grammars is described, which generates parsers by need and processes grammar modifications by updating already existing parsers. We motivate the need for these t...
ISBN:
(纸本)9780897913065
An LR-based parser generator for arbitrary context-free grammars is described, which generates parsers by need and processes grammar modifications by updating already existing parsers. We motivate the need for these techniques in the context of interactive language definition environments, present all required algorithms, and give measurements comparing their performance with that of conventional techniques.
作者：
CHICKERING, JEQUALLS, WBJohn E. Chickering:is a systems analyst with American Management Systems
Inc. in Arlington Virginia. Mr. Chickering received his BS degree in marine engineering from the U.S. Merchant Marine Academy in Kings Point New York in 1981 and his MBA degree in operations research and statistics from the University of Maryland in 1985. He is a licensed third assistant engineer of steam and motor vessels and a member of the Naval Reserve. Mr. Chickering's work includes the design and specification of several management information systems for the U.S. Navy including one that will automate the Navy's engineering drawing management system. Most recently Mr. Chickering has helped develop a workstation for the Navy's Paperless Ship Initiative. William B. Quails:is a management consultant with American Management Systems
Inc. in Arlington Virginia. Mr. Quails received his BA degree in English from the Tulane University in New Orleans Louisiana in 1977 and his MPA degree in management science from the University of Georgia in 1982. Mr. Quails participated in the design and development of the U.S. Navy's Shipboard Non-tactical ADP Program II (SNAP II). Recently Mr. Quails has participated in the design and development of several knowledge-based computer systems using artificial intelligence programming technologies. Mr. Quails is a member of Pi Alpha Alpha an honorary public affairs and administration society.
The U.S. Navy relies heavily on advanced technology to carry out its missions. As a consequence, today's sailors are spending increasing amounts of time maintaining and repairing complex systems and equipment. In ...
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The U.S. Navy relies heavily on advanced technology to carry out its missions. As a consequence, today's sailors are spending increasing amounts of time maintaining and repairing complex systems and equipment. In performing these duties, sailors depend on supporting technical documentation. As the complexity of systems and equipment grow, the volume and complexity of this technical documentation also increases. As a result, technical information, one of the Navy's critical resources, is simultaneously becoming more vital and more difficult to use. The Navy is meeting this challenge by exploring innovative approaches to the management of technical documentation. One example is the Paperless Ship Initiative, which employs optical disk technology as the primary means for document storage. Optical disks can store large volumes of technical information in a small space. One way to take advantage of this auto mated access is to make technical information more readily accessible and easier to use. As an example, a technical manual can be organized on an optical disk into discrete segments of text and indexed for fast retrieval by section, subsection, or paragraph. Furthermore, mechanisms can be developed which allow computer-supported links between logically related segments of the text. This style of interface allows a user to interact directly with the textual passages and to establish new organizational and referential links between them. This style of interface falls under the general category of hypertext (also known as linked text ). The combination of optical disk storage and hypertext offers new possibilities for improving access to large volumes of technical documentation while maintaining all of the advantages of traditional paper-based documentation. This paper begins with a discussion of the need for better technical documentation support. Alternatives that can fulfill this need are reviewed and the role of hypertext is described. The paper illustrates a sample
This paper describes a modularized AI system being built to help improve electromagnetic compatibility (EMC) among shipboard topside equipment and their associated systems. CLEER is intended to act as an easy to use i...
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This paper describes a modularized AI system being built to help improve electromagnetic compatibility (EMC) among shipboard topside equipment and their associated systems. CLEER is intended to act as an easy to use integrator of existing expert knowledge and pre-existing data bases and large scale analytical models. Due to these interfaces; to the need for portability of the software; and to artificial intelligence related design requirements (such as the need for spatial reasoning, expert data base management, model base management, track-based reasoning, and analogical (similar ship) reasoning) it was realized that traditional expert system shells would be inappropriate, although relatively off-the-shelf AI technology could be incorporated. In the same vein, the rapid prototyping approach to expert system design and knowledge engineering was not pursued in favor of a rigorous systems engineering methodology. The critical design decisions affecting CLEER's development are summarized in this paper along with lessons learned to date all in terms of “how,” “why,” and “when” specific features are being developed.
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