Common logic
Encyclopedia
Common logic is a framework for a family of logic languages, based on first-order logic
, intended to facilitate the exchange and transmission of knowledge
in computer
-based systems.
The CL definition permits and encourages the development of a variety of different syntactic forms, called "dialects." A dialect may use any desired syntax, but it must be possible to demonstrate precisely how the concrete syntax of a dialect conforms to the abstract CL semantics, which are based on a model theoretic interpretation. Each dialect may be then treated as a formal language
. Once syntactic conformance is established, a dialect gets the CL semantics for free, as they are specified relative to the abstract syntax only, and hence are inherited by any conformant dialect. In addition, all CL dialects are equivalent (i.e., can be mechanically translated to each other), although some may be more expressive than others.
In general, a less expressive subset of CL may be translated to a more expressive version of CL, but the reverse translation is only defined on a subset of the larger language.
The standard includes specifications for three dialects, the Common Logic Interchange Format (CLIF), the Conceptual Graph Interchange Format (CGIF), and an XML-based notation for Common Logic (XCL).
The semantics of these dialects are defined by their translation to the abstract syntax and semantics of Common Logic.
Many other logic-based languages could also be defined as subsets of CL by means of similar translations; among them are the RDF
and OWL
languages, which have been defined by the W3C.
The ISO standard's development began in June 2003 under Working Group 2 (Metadata) of Sub-Committee 32 (Data Interchange) under ISO/IEC JTC1, and completed in October 2007. A technical corrigendum, correcting some errors in the original standard, is being prepared.
where anyone may participate.
First-order logic
First-order logic is a formal logical system used in mathematics, philosophy, linguistics, and computer science. It goes by many names, including: first-order predicate calculus, the lower predicate calculus, quantification theory, and predicate logic...
, intended to facilitate the exchange and transmission of knowledge
Knowledge
Knowledge is a familiarity with someone or something unknown, which can include information, facts, descriptions, or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject...
in computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
-based systems.
The CL definition permits and encourages the development of a variety of different syntactic forms, called "dialects." A dialect may use any desired syntax, but it must be possible to demonstrate precisely how the concrete syntax of a dialect conforms to the abstract CL semantics, which are based on a model theoretic interpretation. Each dialect may be then treated as a formal language
Formal language
A formal language is a set of words—that is, finite strings of letters, symbols, or tokens that are defined in the language. The set from which these letters are taken is the alphabet over which the language is defined. A formal language is often defined by means of a formal grammar...
. Once syntactic conformance is established, a dialect gets the CL semantics for free, as they are specified relative to the abstract syntax only, and hence are inherited by any conformant dialect. In addition, all CL dialects are equivalent (i.e., can be mechanically translated to each other), although some may be more expressive than others.
In general, a less expressive subset of CL may be translated to a more expressive version of CL, but the reverse translation is only defined on a subset of the larger language.
The ISO Standard
Common Logic is published by ISO as "ISO/IEC 24707:2007 - Information technology — Common Logic (CL): a framework for a family of logic-based languages". It is available for purchase from ISO's catalog, and is freely available at http://standards.iso.org/ittf/PubliclyAvailableStandards/c039175_ISO_IEC_24707_2007%28E%29.zip.The standard includes specifications for three dialects, the Common Logic Interchange Format (CLIF), the Conceptual Graph Interchange Format (CGIF), and an XML-based notation for Common Logic (XCL).
The semantics of these dialects are defined by their translation to the abstract syntax and semantics of Common Logic.
Many other logic-based languages could also be defined as subsets of CL by means of similar translations; among them are the RDF
Resource Description Framework
The Resource Description Framework is a family of World Wide Web Consortium specifications originally designed as a metadata data model...
and OWL
Web Ontology Language
The Web Ontology Language is a family of knowledge representation languages for authoring ontologies.The languages are characterised by formal semantics and RDF/XML-based serializations for the Semantic Web...
languages, which have been defined by the W3C.
The ISO standard's development began in June 2003 under Working Group 2 (Metadata) of Sub-Committee 32 (Data Interchange) under ISO/IEC JTC1, and completed in October 2007. A technical corrigendum, correcting some errors in the original standard, is being prepared.
Implementations
There is an open-source project on SourceForgeSourceForge
SourceForge Enterprise Edition is a collaborative revision control and software development management system. It provides a front-end to a range of software development lifecycle services and integrates with a number of free software / open source software applications .While originally itself...
where anyone may participate.
See also
- Conceptual graphs
- KIFKIFKIF may stand for:* Knowledge Interchange Format* Kingfisher Lake Airport's IATA code* Københavns Idræts Forening, Denmark's oldest athletics club* KIF Kolding, a team handball club based in Kolding, Denmark...
- List of constructed languages#Knowledge representation