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Logical Expressions (logical + expression)

Distribution by Scientific Domains

Information Science and Computing	50%

Selected Abstracts

Consistency of a Shared Versioned Model for Distributed Cooperation

COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 6 2005
B. Firmenich
As a rule the ultimate solution needs many iteration steps. Available CAD-systems support synchronous and distributed work on a document base. Therefore, cooperation between the engineers can be obtained only by the exchange of documents. It is generally known that an overall consistency of the planning material is not adequately addressed by this approach. In this article a solution approach focused upon consistency of the shared planning material in a distributed CAD environment is presented. Because of the nature of the planning process, version management is applied on an object basis. Project data are stored as object versions and relationships. The operations for the distributed cooperation are identified and their impact on the project data is described formally, using logical expressions and set theory. A formulation based upon an algebra of sets is presented. [source]

EquiX,A search and query language for XML

JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 6 2002
Sara Cohen
EquiX is a search language for XML that combines the power of querying with the simplicity of searching. Requirements for such languages are discussed, and it is shown that EquiX meets the necessary criteria. Both a graph-based abstract syntax and a formal concrete syntax are presented for EquiX queries. In addition, the semantics is defined and an evaluation algorithm is presented. The evaluation algorithm is polynomial under combined complexity. EquiX combines pattern matching, quantification, and logical expressions to query both the data and meta-data of XML documents. The result of a query in EquiX is a set of XML documents. A DTD describing the result documents is derived automatically from the query. [source]

Tautologies over implication with negative literals

MLQ- MATHEMATICAL LOGIC QUARTERLY, Issue 4 2010
Hervé Fournier
Abstract We consider logical expressions built on the single binary connector of implication and a finite number of literals (Boolean variables and their negations). We prove that asymptotically, when the number of variables becomes large, all tautologies have the following simple structure: either a premise equal to the goal, or two premises which are opposite literals (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

LOGICAL KNOWLEDGE AND GETTIER CASES

THE PHILOSOPHICAL QUARTERLY, Issue 234 2009
Corine Besson
Knowledge of the basic rules of logic is often thought to be distinctive, for it seems to be a case of non-inferential a priori knowledge. Many philosophers take its source to be different from those of other types of knowledge, such as knowledge of empirical facts. The most prominent account of knowledge of the basic rules of logic takes this source to be the understanding of logical expressions or concepts. On this account, what explains why such knowledge is distinctive is that it is grounded in semantic or conceptual understanding. However, I show that this cannot be the correct account of knowledge of the basic rules of logic, because it is open to Gettier-style counter-examples. [source]