1、BRITISH STANDARD BS ISO/IEC 24707:2007 Information technology Common Logic (CL): a framework for a family of logic-based languages ICS 35.060 BS ISO/IEC 24707:2007 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2007 BSI 2007 ISBN
2、978 0 580 55497 1 National foreword This British Standard is the UK implementation of ISO/IEC 24707:2007. The UK participation in its preparation was entrusted to Technical Committee IST/40, Data management and interchange. A list of organizations represented on this committee can be obtained on req
3、uest to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publication Amd. No. Date Comme
4、nts Reference number ISO/IEC 24707:2007(E)INTERNATIONAL STANDARD ISO/IEC 24707 First edition 2007-10-01 Information technology Common Logic (CL): a framework for a family of logic- based languages Technologies de linformation Logique commune (CL): un cadre pour une famille de langages bass sur la lo
5、gique BS ISO/IEC 24707:2007ii iii Contents Page Foreword vi Introduction vii 1 Scope 1 2 Normative references 2 3 Terms and definitions .2 4 Symbols and abbreviations5 4.1 Symbols 5 4.2 Abbreviations.6 5 Requirements and design overview 6 5.1 Requirements.6 5.2 A family of notations .8 6 Common Logi
6、c abstract syntax and semantics .8 6.1 Common Logic abstract syntax. 8 6.2 Common Logic semantics 13 6.3 Importing and identification on a network 16 6.4 Satisfaction, validity and entailment18 6.5 Sequence markers, recursion and argument lists: discussion 18 6.6 Special cases and translations betwe
7、en dialects 19 7 Conformance20 7.1 Dialect conformance .20 7.2 Application conformance22 7.3 Network conformance .22 Annex A (normative) Common Logic Interchange Format (CLIF) 23 A.1 Introduction23 A.2 CLIF Syntax 24 A.3 CLIF semantics 29 A.4 CLIF conformance .32 Annex B (normative) Conceptual Graph
8、 Interchange Format (CGIF).33 B.1 Introduction33 B.2 CG Core Syntax and Semantics.39 B.3 Extended CGIF Syntax 45 B.4 CGIF conformance.51 Annex C (normative) eXtended Common Logic Markup Language (XCL)54 C.1 Introduction54 C.2 XCL Syntax .54 C.3 XCL Semantics.72 C.4 XCL Conformance72 Bibliography 73
9、BS ISO/IEC 24707:2007iv Figures Page Figure 1 Structure of a text and the taxonomy of the phrase category text 10 Figure 2 Abstract syntax of sentence and its sub-categories10 Figure 3 Abstract syntax of a module10 Figure 4 Abstract syntax of a quantified sentence 11 Figure 5 Abstract syntax of a bo
10、olean sentence .11 Figure 6 Abstract syntax of an atom12 Figure 7 Abstract syntax of a term and term sequence 12 Figure B.1 CG display form for John is going to Boston by bus. 33 Figure B.2 CG display form for “If a cat is on a mat, then it is a happy pet” 34 Figure B.3 CL functions represented by a
11、ctor nodes. 35 Tables Page Table 1 Interpretations of Common Logic Expressions 15 Table A.1 CLIF Semantics 30 Table A.2 Mapping from additional CLIF forms to core CLIF forms 31 Table B.1 Mapping from CL abstract syntax to extended CGIF syntax 52 BS ISO/IEC 24707:2007v Foreword ISO (the International
12、 Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by t
13、he respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of i
14、nformation technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of the joint technical committee is to prepare International Standards. Draft Intern
15、ational Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document
16、 may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. ISO/IEC 24707 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 32, Data management and interchange. BS ISO/IEC 24707:2007vi I
17、ntroduction Common Logic is a logic framework intended for information exchange and transmission. The framework allows for a variety of different syntactic forms, called dialects, all expressible within a common XML-based syntax and all sharing a single semantics. Common Logic has some novel feature
18、s, chief among them being a syntax which is signature-free and permits higher-order constructions such as quantification over classes or relations while preserving a first- order model theory, and a semantics which allows theories to describe intensional entities such as classes or properties. It al
19、so fixes the meanings of a few conventions in widespread use, such as numerals to denote integers and quotation marks to denote character strings, and has provision for the use of datatypes and for naming, importing and transmitting content on the World Wide Web using XML. BS ISO/IEC 24707:20071 Inf
20、ormation technology Common Logic (CL): a framework for a family of logic-based languages 1 Scope This International Standard specifies a family of logic languages designed for use in the representation and interchange of information and data among disparate computer systems. The following features a
21、re essential to the design of this International Standard: Languages in the family have declarative semantics. It is possible to understand the meaning of expressions in these languages without appeal to an interpreter for manipulating those expressions. Languages in the family are logically compreh
22、ensive at its most general, they provide for the expression of arbitrary first-order logical sentences. Interchange of information among heterogeneous computer systems. The following are within the scope of this International Standard: representation of information in ontologies and knowledge bases;
23、 specification of expressions that are the input or output of inference engines; formal interpretations of the symbols in the language. The following are outside the scope of this International Standard: the specification of proof theory or inference rules; specification of translators between the n
24、otations of heterogeneous computer systems; computer-based operational methods of providing relationships between symbols in the logical “universe of discourse” and individuals in the “real world”. This International Standard describes Common Logics syntax and semantics. It defines an abstract synta
25、x and an associated model-theoretic semantics for a specific extension of first- order logic. The intent is that the content of any system using first-order logic can be represented in this International Standard. The purpose is to facilitate interchange of first-order logic-based information betwee
26、n systems. Issues relating to computability using this International Standard (efficiency, optimization, etc.) are not addressed. BS ISO/IEC 24707:20072 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the ed
27、ition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC 2382-15:1999, Information technology Vocabulary Part 15: Programming languages ISO/IEC 10646:2003, Information technology Universal Multiple-Octet Coded Character Se
28、t (UCS) ISO/IEC 14977:1996, Information technology Syntactic metalanguage Extended BNF 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 atom sentence form which has no subsentences as syntactic components NOTE Can be either an equation, or an
29、atomic sentence consisting of a predicate applied to an argument sequence. 3.2 axiom any sentence which is assumed to be true, from which others are derived, or by which they are entailed NOTE In a computational setting, an axiom is a sentence which is never posed as a goal to be proved, but only us
30、ed to prove other sentences. 3.3 Common Logic Interchange Format CLIF KIF-based syntax that is used for illustration purposes in this International Standard NOTE It is one of the concrete syntaxes as described in Annex A. The name “KIF” is not used for this syntax in order to distinguish it from the
31、 commonly used KIF dialects. No assumptions are made in this International Standard with respect to KIF semantics; in particular, no equivalence between CLIF and KIF is intended. 3.4 conceptual graph CG graphical or textual display of symbols arranged according to the style of conceptual graph theor
32、y 3.5 Conceptual Graph Interchange Format CGIF text version of conceptual graphs whose rules of formation conform to Annex B of this International Standard NOTE Sometimes may refer to an example of a character string that conforms to Annex B. Intended to convey exactly the same structure and semanti
33、cs as an equivalent conceptual graph. 3.6 conceptual graph theory form of first-order logic which represents existential quantification and conjunction via the assertion of logical constructs called concepts and relations, which are arranged in an abstract or visually displayed graph NOTE Conceptual
34、 graph theory was introduced by John Sowa 1. BS ISO/IEC 24707:20073 3.7 denotation relationship holding between a name or expression and the thing to which it refers NOTE Also used, with “of,” to mean the entity being named, i.e. the referent of a name or expression. 3.8 dialect concrete instance of
35、 Common Logic syntax that shares (at least some of) the uniform semantics of Common Logic NOTE A dialect may be textual or graphical or possibly some other form. A dialect by definition is also a conforming language (see 7.1 for further details). 3.9 discourse name name whose interpretation is in th
36、e universe of discourse NOTE There is no assumption that different names are interpreted as different individuals. A single individual in the universe of discourse may be denoted by two or more distinct names. 3.10 domain of discourse See universe of discourse. 3.11 eXtensible Common Logic Markup La
37、nguage XCL XML-based syntax for Common Logic 3.12 individual one element of the universe of discourse NOTE The universe of discourse is the set of all individuals. 3.13 Internationalized Resource Identifier IRI string of Unicode characters conforming to the syntax described in 2 and intended for use
38、 as an Internet network identifier syntax which can accommodate a wide variety of international character forms NOTE Intended to replace Uniform Resource Identifier as an Internet standard for network identifiers. 3.14 interpretation formal specification of the meanings of the names in a vocabulary
39、of a Common Logic dialect in terms of a universe of reference. NOTE 1 An interpretation in turn determines the semantic values of all complex expressions of the dialect, in particular the truth values of its sentences. NOTE 2 See 6.2 for a more precise description of how an interpretation is defined
40、. 3.15 Knowledge Interchange Format KIF text-based first order formalism, using a LISP-like list notation NOTE 1 KIF, introduced by Mike Genesereth 3, originated with the Knowledge Sharing Effort sponsored by the US DARPA. NOTE 2 KIF forms the basis for one of the three Common Logic dialects include
41、d in this International Standard. BS ISO/IEC 24707:20074 3.16 operator distinguished syntactic role played by a specified component within a functional term NOTE The denotation of a functional term in an interpretation is determined by the functional extension of the denotation of the operator toget
42、her with the denotations of the remaining components. 3.17 predicate Common Logic distinguished syntactic role played by exactly one component within an atomic sentence NOTE The truth value of an atomic sentence in an interpretation is determined by the relational extension of the denotation of the
43、predicate together with the denotations of the remaining components. 3.18 segregated dialect dialect in which some names are non-discourse names NOTE In an interpretation of a segregated dialect, the denotations of the non-discourse names are in the universe of reference, but not in the universe of
44、discourse. 3.19 sentence Common Logic unit of logical text which is true or false, i.e. which is assigned a truth-value in an interpretation 3.20 sort any subset of the universe of discourse over which some quantifier is allowed to range NOTE Related to the definition of “type” (see 3.24). Generally
45、 used to mean a proper subset of the individuals in the universe of discourse. 3.21 sorted logic logic system (whether first-order or not) which requires that all nonlogical symbols be assigned to a sort 3.22 term Common Logic expression which denotes an individual, consisting of either a name or, r
46、ecursively, a function term applied to a sequence of arguments, which are themselves terms 3.23 traditional first-order logic TFOL traditional mathematical formulations of logic as introduced chiefly by Russell, Whitehead, Peano, Frege, Peirce and Tarski dealing with n-ary predication, the Boolean o
47、perators (including negation) and quantification, and in which every proposition is either determinately true or determinately false NOTE Languages for traditional first-order logic specifically exclude predicate quantifiers and the use of the same name in both predicate and argument position in ato
48、mic sentences, both of which are permitted (though not required) in Common Logic. Languages for traditional first-order logic fall within the category of segregated dialects in CL (see 6.1.3). BS ISO/IEC 24707:20075 3.24 type logical framework in which expressions in the logic are classified into sy
49、ntactic or lexical categories (types) and restricted to apply only to arguments of a fixed type NOTE 1 In practice, a type represents a class of individuals.“Type theory” usually refers to a particular class of such logics in which relation symbols are separated into orders, with relations of order n applying only to those of lower orders. NOTE 2 A type is more restricted than a sort in that a type imposes intensiona
