Normal Forms and Conservative Extension Properties for Query Languages over Collection Types

Limsoon Wong

doi:10.1006/jcss.1996.0037

GEOMETRISATION OF FIRST-ORDER LOGIC

Bulletin of Symbolic Logic ◽

10.1017/bsl.2015.7 ◽

2015 ◽

Vol 21 (2) ◽

pp. 123-163 ◽

Cited By ~ 18

Author(s):

ROY DYCKHOFF ◽

SARA NEGRI

Keyword(s):

Proof Theory ◽

Normal Forms ◽

Order Theory ◽

Order Logic ◽

First Order Logic ◽

Conservative Extension ◽

First Order ◽

First Order Theory ◽

Intermediate Logics ◽

Normal Form Theorem

AbstractThat every first-order theory has a coherent conservative extension is regarded by some as obvious, even trivial, and by others as not at all obvious, but instead remarkable and valuable; the result is in any case neither sufficiently well-known nor easily found in the literature. Various approaches to the result are presented and discussed in detail, including one inspired by a problem in the proof theory of intermediate logics that led us to the proof of the present paper. It can be seen as a modification of Skolem’s argument from 1920 for his “Normal Form” theorem. “Geometric” being the infinitary version of “coherent”, it is further shown that every infinitary first-order theory, suitably restricted, has a geometric conservative extension, hence the title. The results are applied to simplify methods used in reasoning in and about modal and intermediate logics. We include also a new algorithm to generate special coherent implications from an axiom, designed to preserve the structure of formulae with relatively little use of normal forms.

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Normal forms and conservative properties for query languages over collection types

Proceedings of the twelfth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems - PODS '93 ◽

10.1145/153850.153853 ◽

1993 ◽

Cited By ~ 19

Author(s):

Limsoon Wong

Keyword(s):

Normal Forms ◽

Query Languages

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Normal Forms and Bifurcation of Planar Vector Fields

10.1017/cbo9780511665639 ◽

1994 ◽

Cited By ~ 232

Author(s):

Shui-Nee Chow ◽

Chengzhi Li ◽

Duo Wang

Keyword(s):

Vector Fields ◽

Normal Forms ◽

Planar Vector Fields ◽

Planar Vector

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Classification of means and methods of the Web semantic retrieval

PROBLEMS IN PROGRAMMING ◽

10.15407/pp2017.01.030 ◽

2017 ◽

pp. 030-050

Author(s):

J.V. Rogushina ◽

Keyword(s):

Search Engines ◽

Domain Knowledge ◽

Information Needs ◽

Web Search ◽

User Interaction ◽

Query Languages ◽

Semantic Search ◽

Semantic Retrieval ◽

The Web

Problems associated with the improve ment of information retrieval for open environment are considered and the need for it’s semantization is grounded. Thecurrent state and prospects of development of semantic search engines that are focused on the Web information resources processing are analysed, the criteria for the classification of such systems are reviewed. In this analysis the significant attention is paid to the semantic search use of ontologies that contain knowledge about the subject area and the search users. The sources of ontological knowledge and methods of their processing for the improvement of the search procedures are considered. Examples of semantic search systems that use structured query languages (eg, SPARQL), lists of keywords and queries in natural language are proposed. Such criteria for the classification of semantic search engines like architecture, coupling, transparency, user context, modification requests, ontology structure, etc. are considered. Different ways of support of semantic and otology based modification of user queries that improve the completeness and accuracy of the search are analyzed. On base of analysis of the properties of existing semantic search engines in terms of these criteria, the areas for further improvement of these systems are selected: the development of metasearch systems, semantic modification of user requests, the determination of an user-acceptable transparency level of the search procedures, flexibility of domain knowledge management tools, increasing productivity and scalability. In addition, the development of means of semantic Web search needs in use of some external knowledge base which contains knowledge about the domain of user information needs, and in providing the users with the ability to independent selection of knowledge that is used in the search process. There is necessary to take into account the history of user interaction with the retrieval system and the search context for personalization of the query results and their ordering in accordance with the user information needs. All these aspects were taken into account in the design and implementation of semantic search engine "MAIPS" that is based on an ontological model of users and resources cooperation into the Web.

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METHODS OF REDUCING OF LARGE BOOLEAN FORMULAS REPRESENTED IN A CONJUNCTIVE NORMAL FORM FOR DETERMINING THEIR SATISFIABILITY

STATE AND DEVELOPMENT PROSPECTS OF AGRIBUSINESS. In the frame of the XXIII Agribusiness Forum of the South of Russia and the Exhibition «Interagromash» Volume 1 ◽

10.23947/interagro.2020.1.472-475 ◽

2020 ◽

Author(s):

N.I. Gdansky ◽

◽

A.A. Denisov ◽

Keyword(s):

Normal Form ◽

Normal Forms ◽

Conjunctive Normal Form ◽

Boolean Formulas

The article explores the satisfiability of conjunctive normal forms used in modeling systems.The problems of CNF preprocessing are considered.The analysis of particular methods for reducing this formulas, which have polynomial input complexity is given.

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