1、BSI Standards Publication BS ISO/IEC 13250-5:2015 Information technology T o p i c M a p s Part 5: Reference modelBS ISO/IEC 13250-5:2015 BRITISH STANDARD National foreword This British Standard is the UK implementation of ISO/IEC 13250-5:2015. The UK participation in its preparation was entrusted t
2、o Technical Committee IST/41, Document description and processing language. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correc
3、t application. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 63264 8 ICS 35.240.30 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and St
4、rategy Committee on 31 March 2015. Amendments/corrigenda issued since publication Date T e x t a f f e c t e dBS ISO/IEC 13250-5:2015Reference number ISO/IEC 13250-5:2015(E) ISO/IEC 2015INTERNATIONAL STANDARD ISO/IEC 13250-5 First edition 2015-04-01 Information technology Topic Maps Part 5: Referenc
5、e model Technologies de linformation Plans relatifs des sujets Partie 5: Modle de rference BS ISO/IEC 13250-5:2015 ISO/IEC 13250-5:2015(E) COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2015 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in
6、 any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case po
7、stale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO/IEC 2015 All rights reservedBS ISO/IEC 13250-5:2015 ISO/IEC 13250-5:2015(E) ISO/IEC 2015 All rights reserved iii Contents Page Foreword iv Introduction . v
8、1 Scope 1 2 Subjects 1 3 Subject Proxies and Maps 1 4 Ontological Commitments 2 5 Navigation 3 6 Merging . 4 7 Constraints . 5 8 Map Legends 6 9 Conformance . 6 Annex A (normative) Path Language 7 Annex B (informative) Notation . 11 Bibliography 12 BS ISO/IEC 13250-5:2015 ISO/IEC 13250-5:2015(E) iv
9、ISO/IEC 2015 All rights reserved Foreword ISO (the International 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 Inter
10、national Standards through technical committees established by the 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
11、 with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1.
12、 In particular the different approval criteria needed for the different types of document should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements
13、of this document may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations rece
14、ived (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs a
15、dherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: For e word Sup plement a ry inform a tio n ISO/IEC 13250-5 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 34, Document description and processing languages
16、. ISO/IEC 13250 consists of the following parts, under the general title Information technology Topic Map: Part 2: Data model Part 3: XML syntax Part 4: Canonicalization Part 5: Reference model Part 6: Compact syntax BS ISO/IEC 13250-5:2015 ISO/IEC 13250-5:2015(E) ISO/IEC 2015 All rights reserved v
17、Introduction The Topic Maps family of standards is designed to facilitate the gathering of all the information about a subject at a single location. The information about a subject includes its relationships to other subjects; such relationships may also be treated as subjects (subject-centric). ISO
18、/IEC 13250-2:2006 1 provides a foundation for syntaxes and notations, such as those defined in ISO/IEC 13250-3 Topic Maps XML Syntax 2 and ISO/IEC 13250-4 Topic Maps Canonicalization 3. Of necessity, ISO/IEC 13250-2:2006 1 makes ontological commitments in terms of how particular subjects are identi_
19、ed (topics, associations, occurrences), what properties are required, the tests to be used to determine whether two or more proxies represent the same subject, and other matters. This part of ISO/IEC 13250 defines TMRM (Topic Maps Reference Model), which is more abstract and has fewer ontological co
20、mmitments. Its purpose is to serve as a minimal, conceptual foundation for subject-centric data models such as ISO/IEC 13250-2:2006 1, and to supply ontologically neutral terminology for disclosing these. It de_nes what is required to enable the mapping of different subject-centric data models toget
21、her to meet the overall goal of the Topic Maps standards, that each subject has a single location for all the information about it. TMRM also provides a formal foundation for related Topic Maps standards such as the ISO/IEC 19756 Topic Maps Constraint Language (TMCL) 4. BS ISO/IEC 13250-5:2015BS ISO
22、/IEC 13250-5:2015 1 Scope This part of ISO/IEC 13250 species a formal model for subject maps, minimal access func- tionality and information retrieval from subject maps and a constraint framework governing the interpretation of subject maps. Particular formalisms to constrain subject maps are not co
23、vered by this part of ISO/IEC 13250. 2 Subjects A subject is dened in the Topic Maps family of standards as something which . can be anything whatsoever, regardless of whether it exists or has any other specic characteristics, about which anything whatsoever may be asserted by any means whatsoever (
24、ISO/IEC 13250- 2:2006 5.3.1). According to the TMRM, there is only one representative for subjects: subject proxies (proxies). 3 Subject Proxies and Maps Proxies consist of properties. These are key/value pairs which|in turn|may contain references to other proxies. This recursive relationship is den
25、ed via two postulated sets. One is the nite set of proxy labels,L. The second set isV, a nite set of values. It contains values (such as numbers, strings, etc.), and all the labels inL. A property is the pairhk;vi2LV . The rst component of this pair is called the key, the other the value of the prop
26、erty. The set of all such properties is denoted asP. Keys in properties are always labels, the values in properties may be labels or any other value from the value setV. EXAMPLE 1 Given the label shoesize and the integer 43, thenhshoesize;43i is a property. A proxy is a nite set of properties, fp 1
27、;:;p n g, with p i 2P (see Fig. 1). The multiset of all keys of a proxy x is retrievable via the function keys(x), i.e. keys can occur more than once in a proxy with dierent values. The multiset of all values is values(x). Particular values may appear more than once in one proxy. EXAMPLE 2 A particu
28、lar person may be represented by the following proxy:fhshoesize;43i; hbeardcolor;whitei;hbeardlength;verylongig 1 - INTERNATIONAL STANDARD ISO/IEC 13250-5:2015(E) - Information technology Topic Maps Part 5: Reference Model ISO/IEC 201 5 All rights reservedBS ISO/IEC 13250-5:2015 ISO/IEC 13250-5:2015
29、(E) Figure 1 Proxy Structure The set of all proxiesX is the set of all subsets ofP,X = 2 P . The connection between proxies and their labels is modeled with a partial, injective function :X7!V. It returns the label for a given proxy x whereby two dierent proxies never share the same label. The funct
30、ion is extended to values in that v =v. NOTE 1 A proxy is dened by the totality of its properties. Individual properties can provide a basis for mapping multiple proxies of the same subject to each other. NOTE 2 One proxy may contain several properties which all share the same key but have dierent v
31、alues; or share the same value, but have diering keys. A subject map (map) is a nite set of proxies. The set of all such maps is denoted asM. As maps are simply sets of proxies, generic merging of maps is achieved via set union, mm 0 . NOTE 3 The model of subject maps described herein assumes no par
32、ticular implementation technology or strategy. 4 Ontological Commitments This part of ISO/IEC 13250 deliberately leaves undened the methods whereby subject proxies are derived or created. No specic mechanism of subject identication is inherent in or mandated by this part of ISO/IEC 13250, nor does i
33、t predene any subject proxies. NOTE 1 Any subject proxy design choices would be specic to a particular application domain and would exclude equally valid alternatives that might be appropriate or necessary in the contexts of various requirements. Two types of relationships, ako (subclass of) and isa
34、 (instance of), are dened. These predicates are always interpreted relative to a given map m: a) Two proxies c;c 0 can be in a subclass-superclass relationship, ako m m m. In such a case, the same relationship can be stated either c is a subclass of c 0 or c 0 is a superclass of c. ako m is reexive
35、and transitive. Reexive means that any proxy is a subclass of itself, regardless whether the proxy is used as a class in the map or not: x ako m x for all x2m. Transitive means that if a proxy c is a subclass of another, c 0 , and that subclasses c 00 , then c is also a subclass of c 00 , i.e. if c
36、ako m c 0 and c 0 ako m c 00 then also c ako m c 00 must be true. 2 ISO/IEC 201 5 All rights reservedBS ISO/IEC 13250-5:2015 ISO/IEC 13250-5:2015(E) NOTE 2 Circular subclass relationships may exist in a map. b) Two proxies a;c can be in an isa relationship, isa m m m. In such a case, the same relati
37、onship can be stated either a is an instance of c or c is the type of a. The isa relationship is non-reexive, i.e. x isa m x for no x2 m, so that no proxy can be an instance of itself. Additionally, whenever a proxy a is an instance of another c, then a is an instance of any superclass of c: if x is
38、a m c and c ako m c 0 , then x isa m c 0 is true. NOTE 3 Other denitions of the above relationships are possible with dierent properties than dened by the TMRM. Such denitions would appear in legends and would be distinguished from those dened in the TMRM. NOTE 4 This part of ISO/IEC 13250 does not
39、mandate any particular way of representing such rela- tionships inside a map. One option is to model such a relationship simply with a property using a certain key (say type). An alternative way is to provide a proxy for each such relationship. Such relationship proxies could, for example, have prop
40、erties whose keys are instance andclass, or respectively subclass and superclass. 5 Navigation Given a mapm and particular proxiesx;y2m in it, the following primitive navigation operators are dened: a) A postx operator # to return the multiset of all local keys of a given proxy: x# =keys(x) (1) b) A
41、 postx operator “ m to retrieve the multiset of remote keys of a proxy inside m. These are those where the given proxy (more precisely its label) is the value in another proxy: x“ m = kj9y2m:hk; xi2y (2) This is easily generalized to an operator for all values: v“ m = kj9y2m:hk; vi2y (3) c) A postx
42、operator !k to retrieve the multiset of local values for a particular key k2L: x!k = vj9hk;vi2x (4) Using the predicate ako m the operator can be generalized to honor subclasses of the key k: x! m k = vj9hk 0 ;vi2x: k 0 ako m k (5) d) A postx operator m k which navigates to all proxies in the given
43、map which use a given value v together with a certain key k2L: v m k = x2mj9hk; vi2x (6) Using the predicate ako m the operator can be generalized to honor subclasses of the key k: v m k = x2mj9hk 0 ; vi2x: k 0 ako m k (7) 3 ISO/IEC 201 5 All rights reservedBS ISO/IEC 13250-5:2015 ISO/IEC 13250-5:20
44、15(E) It is straightforward to generalize all these navigation operators on individual proxies and values to multisets of them. As a consequence the result of one postx can be used as startpoint for another postx, enabling the building of postx chains . This primitive path language is denoted asP M
45、. NOTE 1 P M only serves as a minimal baseline for functionality to be provided by conforming imple- mentations. It can be also used as the basis for a formal semantics for higher-level query and constraint languages. Annex A describes one. 6 Merging Generic merging of maps only combines two (or mor
46、e) proxy sets. Application-specic merging includes a second aspect. A mechanism has to be found to state whether|in a given map|two proxies are regarded to be about the same subject. Then all such equivalent proxies have to be actually merged. NOTE 1 How subject sameness is determined and how the ac
47、tual proxy merging is eectively done is not constrained by this part of ISO/IEC 13250. Such a process may be dened as having inputs that consist only of the proxies to be merged. Alternatively, the inputs may also include other information that may appear either inside the map or elsewhere in the me
48、rging processs environment. NOTE 2 Given the appropriate expressitivity of the used constraint language, such equivalence and the consequent merging process can be described with a constraint. Merging is modeled with a partial function ./:XXE 7!X . It takes two proxies and an|otherwise unconstrained|environmentE as parameters and produces a new proxy. In the special case that the environment has no inuence in this process, ./ is an inx operator XX
