From csus.edu!uop!pacbell.com!ihnp4.ucsd.edu!agate!spool.mu.edu!uwm.edu!vixen.cso.uiuc.edu!howland.reston.ans.net!pipex!uknet!comlab.ox.ac.uk!zforum-request Fri Dec 2 06:42:09 1994 Newsgroups: comp.specification.z,news.answers,comp.answers Path: csus.edu!uop!pacbell.com!ihnp4.ucsd.edu!agate!spool.mu.edu!uwm.edu!vixen.cso.uiuc.edu!howland.reston.ans.net!pipex!uknet!comlab.ox.ac.uk!zforum-request From: zforum-request@comlab.ox.ac.uk Subject: comp.specification.z Frequently Asked Questions (Monthly) Message-ID: Followup-To: comp.specification.z Summary: Information about the Z formal specification notation Originator: news@topaz.comlab Supersedes: Sender: news@comlab.ox.ac.uk Reply-To: zforum-request@comlab.ox.ac.uk Organization: Oxford University Computing Laboratory, UK Date: Thu, 1 Dec 1994 02:00:04 GMT Approved: news-answers-request@MIT.Edu Expires: Thu, 12 Jan 1995 02:00:02 GMT Lines: 413 Xref: csus.edu comp.specification.z:1638 news.answers:33132 comp.answers:8647 Archive-name: z-faq Last-modified: 19 November 1994 Maintainer: Jonathan Bowen URL: file://ftp.comlab.ox.ac.uk/pub/Zforum/faq NAME: comp.specification.z STATUS: unmoderated PURPOSE: Discussion concerning the formal specification notation Z. (If you have read this before, changed and new sections since the previously issued version are marked with `|' in the right hand margin.) Note: nearly all UK telephone numbers will have a "1" prefixed to them in future. Currently there is a changeover period in operation. The UK contact telephone numbers have been updated en masse in this message. If there are any mistakes, please contact the email address at the end of the message. Thank you. Questions have been marked with "Subject:" at the start of the line to allow some newsreaders to scan them easily (e.g., "^G" within "rn"). This FAQ message is available on-line on the World Wide Wed (WWW) hypertext http://www.cis.ohio-state.edu/hypertext/faq/usenet/z-faq/faq.html page where it is split into convenient sections. Subject: What is it? The comp.specification.z electronic USENET newsgroup was established in June 1991 and is intended to handle messages concerned with the formal specification notation Z (pronounced `zed'). It has an estimated readership of around 45,000 people worldwide. Z, based on set theory and first order predicate logic, has been developed at the Programming Research Group (PRG) at the Oxford University Computing Laboratory and elsewhere since the late 1970s. It is now used by industry as part of the software (and hardware) development process in both the UK and the US. It is currently undergoing international ISO standardization. Comp.specification.z provides a convenient forum for messages concerned with recent developments and the use of Z. Pointers to and reviews of recent books and articles are particularly encouraged. These will be included in the Z bibliography (see below) if they appear in comp.specification.z. Subject: What if I know someone interested without access to USENET news? There is an associated Z FORUM electronic mailing list that was initiated in January 1986 by Ruaridh Macdonald, RSRE, UK. Articles are now automatically cross-posted between comp.specification.z and the mailing list for those whose do not have access to USENET news. This may apply especially to industrial Z users who are particularly encouraged to subscribe and post their experiences to the list. Please contact with your name, address and email address to join the mailing list (or if you change your email address or wish to be removed from the list). Readers are strongly urged to read the comp.specification.z newsgroup rather than the Z FORUM mailing list if possible. Messages for submission to the Z FORUM mailing list and the comp.specification.z newsgroup may be emailed to . This method of posting is particularly recommended for important messages like announcements of meetings since not all messages posted on comp.specification.z reach the PRG. A mailing list for the Z User Meeting educational issues session has been set by Neville Dean, Anglia Polytechnic University, UK. Anyone interested may join by emailing with your contact details. A specialist electronic mailing for discussion of SAZ, a combination of the structured method SSADM and Z also exists. To join, contact . Subject: What if I know someone interested without access to email? If you wish to join the postal Z mailing list, please send your address to Amanda Kingscote, Praxis plc, 20 Manvers Street, Bath BA1 1PX, UK (tel +44-1225-444700, fax +44-1225-465205, email ). This will ensure you receive details of Z meetings, etc., particularly for people without access to electronic mail. Subject: How can I join in? If you are currently using Z, you are welcome to introduce yourself to the newsgroup and Z FORUM list by describing your work with Z or raising any questions you might have about Z which are not answered here. You may also advertize publications concerning Z which you or your colleagues produce. These may then be added to the master Z bibliography maintained at the PRG (see below). Subject: Where are Z-related files archived? Information on the World Wide Web (WWW) is available under the | http://www.comlab.ox.ac.uk/archive/z.html page. See also the | http://www.comlab.ox.ac.uk/archive/formal-methods.html page on formal methods in general. The WWW global hypertext system is accessible using the "mosaic" or "lynx" programs for example. Contact your system manager if WWW access is not available on your system. Some of the archive is also available via anonymous FTP on the Internet under the ftp.comlab.ox.ac.uk:/pub/Zforum directory. Type the command "ftp ftp.comlab.ox.ac.uk" (or alternatively "ftp 163.1.27.2" if this does not work) and use "anonymous" as the login id and your email address as the password when prompted. The FTP command "cd pub/Zforum" will get you into the Z archive directory. The file ftp.comlab.ox.ac.uk:/pub/Zforum/README gives some general information and ftp.comlab.ox.ac.uk:/pub/Zforum/00index gives a list of the files. (Retrieve these using the FTP command "get README", for example.) There is an automatic electronic mail-based electronic archive server which allows access to some of the archive such as most messages on comp.specification.z and Z FORUM, as well as a selection of other Z-related text files. Send an email message containing the command "help" to for further information on how to use the server. A command of "index z" will list the Z-related files. If you have serious trouble accessing the archive server, please contact the address . Subject: What tools are available? Various tools for formatting, type-checking and aiding proofs in Z are available. A free LaTeX style file and documentation can be obtained from the PRG archive server. To receive this via email, send a message containing the command "send z zed.sty zguide.tex" to the PRG archive server (or access the ftp.comlab.ox.ac.uk:/pub/Zforum/zed.sty and ftp.comlab.ox.ac.uk:/pub/Zforum/zguide.sty files). A newer style "csp_zed.sty" is available in the same location, which uses the new font selection scheme and covers CSP and Z symbols. A style for Object-Z "oz.sty" with a guide "oz.tex" is also accessible. The fuzz package, a syntax and type checker with a LaTeX style option and fonts, is available from J.M. Spivey Computing Science Consultancy, 34, Westlands Grove, Stockton Lane, York YO2 0EF, UK. It is compatible with the second edition of Spivey's Z Reference Manual (see below). Contact Mike Spivey (email ) for further information. Alternatively send the command "send z fuzz" to the PRG archive server or access ftp.comlab.ox.ac.uk:/pub/Zforum/fuzz for brief information and an order form. CADiZ, a Unix-based suite of tools for checking and typesetting Z specifications. CADiZ also supports previewing and interactive investigation of specifications. It is available from York Software Engineering, University of York, York YO1 5DD, UK (tel +44-1904-433741, fax +44-1904-433744). CADiZ supports a language like that of the Z Base Standard (Version 1.0). A particular extension allows one specification document to import another, including the mathematical toolkit as one such document. Typesetting Support is available for both troff and for LaTeX. Browsing operations include display of information deduced by the type-checker (e.g. types of expressions and uses of variables), expansion of schemas, pre- and post-condition calculation, and simplification by the one-point rule. Currently work is on-going to provide support for refinement of Z specifications to Ada programs through a literate program development method and integrated proof facilities. Further information is available from David Jordan at York on . ProofPower is a suite of tools supporting specification and proof in Higher-Order Logic (HOL) and in Z. Short courses on ProofPower-Z are available as demand arises. Information about ProofPower can be obtained automatically from . Contact Roger Jones, International Computers Ltd, Eskdale Road, Winnersh, Wokingham, Berkshire RG11 5TT, UK (tel +44-1734-693131 ext 6536, fax +44-1734-697636, email or ) for further details. Zola is a tool that supports the production and typesetting of Z specifications, including a type-checker and a Tactical Proof System. The tool is sold commercially and available to academic users at a special discount. For further information, contact K. Ashoo, Imperial Software Technology, 62-74 Burleigh Street, Cambridge CB1 1DJ, UK (tel +44-1223-462400, fax +44-1223-462500, email ). ZTC is a Z type checker for the PC and Sun available free of charge via anonymous FTP in compressed Unix tar format under the directory ise.cs.depaul.edu:/dist (140.192.32.117) and also from the Z archive at Oxford under the ftp.comlab.ox.ac.uk:/pub/Zforum/ZTC-1.3 directory. It is available for educational and non-profit uses and is part of an ongoing research project developing supporting tools for using Z. Contact Xiaoping Jia on for further information. Formaliser is a syntax-directed Z editor and type checker, running under Microsoft Windows, available from Logica Cambridge. Contact Susan Stepney, Logica Cambridge Limited, Betjeman House, 104 Hills Road, Cambridge CB2 1LQ, UK (tel +44-1223-66343, email ) for further information. DST-fuzz is a set of tools based on the fuzz package by Mike Spivey, supplying a Motif based user interface for LaTeX based pretty printing, syntax and type checking. A CASE tool interface allows basic functionality for combined application of Z together with structured specifications. The tools are integrated into SoftBench. For further information contact Hans-Martin Hoercher, DST Deutsche System-Techik GmbH, Edisonstr. 3, D-24145 Kiel, Germany (tel +49-(0)431-7109-478, fax +49-(0)431-7109-503, email ). The B-Tool can be used to check proofs concerning parts of Z specifications. This is licensed by Edinburgh Portable Compilers Ltd, 17 Alva Street, Edinburgh EH2 4PH, UK (tel +44-131-225-6262, fax +44-131-225-6644). Contact the Distribution Manager (email ) for further information. The B-Toolkit is a set of integrated tools which fully supports the B-Method for formal software development and is available from B-Core (UK) Limited, Magdalen Centre, The Oxford Science Park, Oxford OX4 4GA, UK. For further details, contact Ib Sorensen (tel +44-1865-784520, fax +44-1865-784518, email ). A survey of Z tools may be obtained from Colin Parker, Systems Process Department, W376C, British Aerospace, Warton Aerodrome, Warton, Preston PR4 1AX, UK. Subject: How can I learn about Z? There are a number of courses on Z run by industry and academia. Oxford University offers industrial short courses in the use Z. As well as introductory courses, recent newly developed material includes advanced Z-based courses on proof and refinement, partly based around the B-Tool. Courses are held in Oxford, or elsewhere (e.g., on a company's premises) if there is enough demand. For further information, contact Jim Woodcock (tel +44-1865-283514, fax +44-1865-273839, email ). Logica UK Limited offer a five day course on Z and a three day introductory course on formal methods (mainly Z). For dates and prices contact Janet Quickenden +44-1223-66343 ext 4845. Praxis Systems plc runs a range of Z (and other formal methods) courses. For details contact Anthony Hall on +44-1225-444700 or . Formal Systems (Europe) Ltd run a range of Z, CSP and other formal methods courses, primarily in the US and with such lecturers as Jim Woodcock and Bill Roscoe (both lecturers at the PRG). For dates and prices contact Joy Reed (tel +44-1865-283503, email ) at the PRG or Kate Pearson (tel +44-1865-728460) at Formal Systems. DST Deutsche System-Technik runs a collection of courses for either Z or CSP, mainly in Germany. These courses range from half day introductions to formal methods and Z to one week introductory or advanced courses, held either at DST, or elsewhere. For further information contact Hans-Martin Hoercher, DST Deutsche System-Techik GmbH, Edisonstr. 3, D-24145 Kiel, Germany (tel +49-(0)431-7109-478, fax +49-(0)431-7109-503, email ). Subject: What has been published about Z? A searchable on-line Z bibliography is available on the World-Wide Web | under http://www.comlab.ox.ac.uk/archive/z/bib.html in BibTeX format. | For those without WWW access, an older compressed version is available via anonymous FTP under ftp.comlab.ox.ac.uk:/pub/Zforum/z.bib.Z (and ftp.comlab.ox.ac.uk:/pub/Zforum/z.ps.Z in PostScript format). Information on Oxford University Programming Research Group (PRG) Technical Monographs and Reports, including many on Z, is available from the librarian (tel +44-1865-273837, fax +44-1865-273839, email ). "Formal Methods: A Survey" by S.Austin & G.I.Parkin, March 1993 includes information on the use and teaching of Z in industry and academia. Contact DITC Office, Formal Methods Survey, National Laboratory, Teddington, Middlesex TW11 0LW, UK (tel +44-181-943-7002, fax +44-181-977-7091) for a copy. The following books largely concerning Z have been or are due to be published (in approximate chronological order): I.Hayes (ed.), Specification case studies, Prentice Hall International Series in Computer Science, 1987. (2nd ed., 1993) J.M.Spivey, Understanding Z: a specification language and its formal semantics, Cambridge University Press, 1988. D.Ince, An introduction to discrete mathematics, formal system specification and Z, Oxford University Press, 1988. (2nd ed., 1993) J.C.P.Woodcock & M.Loomes, Software engineering mathematics, Pitman, 1988. J.M.Spivey, The Z notation: a reference manual, Prentice Hall International Series in Computer Science, 1989. (2nd ed., 1992) [Widely used as the current de facto standard for Z.] A.Diller, Z: an introduction to formal methods, Wiley, 1990. J.E.Nicholls (ed.), Z user workshop, Oxford 1989, Springer-Verlag, Workshops in Computing, 1990. B.Potter, J.Sinclair & D.Till, An introduction to formal specification and Z, Prentice Hall International Series in Computer Science, 1991. D.Lightfoot, Formal specification using Z, MacMillan, 1991. A.Norcliffe & G.Slater, Mathematics for software construction, Ellis Horwood, 1991. J.E.Nicholls (ed.), Z user workshop, Oxford 1990, Springer-Verlag, Workshops in Computing, 1991. I.Craig, The formal specification of advanced AI architectures, Ellis Horwood, 1991. M.Imperato, An introduction to Z, Chartwell-Bratt, 1991. J.B.Wordsworth, Software development with Z, Addison-Wesley, 1992. S.Stepney, R.Barden & D.Cooper (eds.), Object orientation in Z, Springer-Verlag, Workshops in Computing, August 1992. J.E.Nicholls (ed.), Z user workshop, York 1991, Springer-Verlag, Workshops in Computing, 1992. D.Edmond, Information Modeling: Specification and Implementation, Prentice Hall, 1992. J.P.Bowen & J.E.Nicholls (eds.), Z user workshop, London 1992, Springer-Verlag, Workshops in Computing, 1993. S.Stepney, High integrity compilation: A case study, Prentice Hall, 1993. M.McMorran & S.Powell, Z guide for beginners, Blackwell Scientific, 1993. K.C.Lano & H.Haughton (eds.), Object-oriented specification case studies, Prentice Hall International Object-Oriented Series, 1993. B.Ratcliff, Introducing Specification Using Z: A Practical Case Study Approach, McGraw-Hill, 1994. A.Diller, Z: an introduction to formal methods, 2nd ed., Wiley, 1994. J.P.Bowen & J.A.Hall (eds.), Z user workshop, Cambridge 1994, Springer-Verlag, Workshops in Computing, 1994. R.Barden, S.Stepney, D.Cooper, Z in practice, Prentice Hall | BCS Practitioner Series, 1994. | Announced: J.C.P.Woodcock & J.Davies, Using Z: specification, proof and refinement, Prentice Hall International Series in Computer Science, 1995? (In preparation) Subject: What is object-oriented Z? Several object-oriented extensions to or versions of Z have been proposed. The book "Object orientation in Z", listed above, is a collection of papers describing various OOZ approaches - Hall, ZERO, MooZ, Object-Z, OOZE, Schuman&Pitt, Z++, ZEST and Fresco (an OO VDM method) - in the main written by the methods' inventors, and all specifying the same two examples. A more recent book entitled "Object-oriented specification case studies" surveys the principal methods and languages for formal object-oriented specification, including Z-based approaches. Subject: How can I run Z? Z is a (non-executable in general) specification language, so there is no such thing as a Z compiler/linker/etc. as you would expect for a programming language. Some people have looked at animating subsets of Z for rapid prototyping purposes, using logic and functional programming for example, but this work is preliminary and is not really the major point of Z, which is to increase human understandability of the specified system and allow the possibility of formal reasoning and development. However, Prolog seems to be the main favoured language for Z prototyping and some references may be found in the Z bibliography (see above). Subject: Where can I meet other Z people? The 8th Z User Meeting (ZUM'95) was held on 29-30 June 1994 at St. John's College, University of Cambridge, UK in association with BCS FACS. The 9th Z User Meeting is planned for 7-8 September 1995 in Limerick, Ireland. For general enquiries, contact the Conference Chair, Jonathan Bowen (tel +44-1865-283512, fax +44-1865-273839, email ). Further details will be issued on comp.specification.z in due course. The proceedings for Z User Meetings have been published in the Springer-Verlag Workshops in Computing series since the 4th meeting in 1989. A Call for Papers for ZUM'95 is available from http://www.comlab.ox.ac.uk/archive/z/zum95.html via WWW or ftp.comlab.ox.ac.uk:/pub/Zforum/zum95 via anonymous FTP. The deadline for paper submissions is 9th December 1994. The 6th Refinement Workshop was held at City University, London, UK, 5-7 January 1994. The Programme Chair was David Till, Dept of Computer Science, City University, Northampton Square, London, EC1V 0HB, UK (tel +44-171-477-8552, email ). The proceedings for these workshops are currently published in the Springer-Verlag Workshops in Computing series. The second FME (Formal Methods Europe) Symposium was held in | Barcelona, Spain, 24-28 October 1994. The proceedings are available | as Springer LNCS 873. The next FME Symposium will be held in 1996 in | Oxford, UK. The chairman of FME is Martyn Thomas, Praxis plc, 20 | Manvers Street, Bath BA1 1PX, UK (tel +44-1225-444700, email | ). | FORTE addresses formal techniques and testing methodologies | applicable to distributed systems such as Estelle, Lotos, SDL, ASN.1, | Z, etc. The IFIP WG6.1 7th International Conference on Formal | Description Techniques for Distributed Systems and Communications | Protocols (FORTE'94) was held at Berne, Switzerland, 4-7 October 1994. | The 8th conference (FORTE'95) will be held in Montreal (Quebec), | Canada, 17-20 October 1995. For further information, see the WWW page: | http://www.comlab.ox.ac.uk/archive/formal-methods/conf/FORTE95.html | Details of Z-related meetings may be advertized on comp.specification.z if desired. All the above meetings are likely to be repeated in some form. Subject: What is the Z User Group? The Z User Group was set up in 1992 to oversee Z-related activities, and the Z User Meetings in particular. As a subscriber to comp.specification.z, ZFORUM or the postal mailing list, you may consider yourself a member of the Z User Group. There are currently no charges for membership, although this is subject to review if necessary. Contact for further information. Subject: How can I obtain the draft Z standard? The proposed Z standard under ISO/IEC JTC1/SC22 is available electronically via anonymous FTP *only* (not via the mail server since it is too large) from the Z archive at Oxford in compressed PostScript format. Version 1.0 of the draft standard is accessible as the file ftp.comlab.ox.ac.uk:/pub/Zforum/zstandard1.0.ps.Z together with a annex in the ftp.comlab.ox.ac.uk:/pub/Zforum/zstandard-annex1.0.ps.Z file. It is also available in printed form from the Oxford University Computing Laboratory librarian (tel +44-1865-273837, fax +44-1865-273839, email ) by requesting Technical Monograph number PRG-107. Subject: Where else is Z discussed? The BCS FACS (British Computer Society Formal Aspects of Computer Science special interest group) and FME (Formal Methods Europe) are two organizations interested in formal methods in general. Contact BCS FACS, Dept of Computer Studies, Loughborough University of Technology, Loughborough, Leicester LE11 3TU, UK (tel +44-1509-222676, fax +44-1509-211586, email ) for further information. A "FACS Europe" newsletter is issued to members of FACS and FME. Please send suitable Z-related material to the Z column editor, David Till, Dept of Computer Science, City University, Northampton Square, London, EC1V 0HB, UK (tel +44-171-477-8552, email ) for possible publication. Material from articles appearing on the comp.specification.z newsgroup may be included if considered of sufficient interest (with permission from the originator if possible). It would be helpful for posters of articles on comp.specification.z to indicate if they do not want further distribution for any reason. Subject: How does VDM compare with Z? See I.J.Hayes, C.B.Jones & J.E.Nicholls, Understanding the differences between VDM and Z, FACS Europe, series I, 1(1):7-30, Autumn 1993 available as an on-line Technical Report from Manchester under ftp.cs.man.ac.uk:/pub/TR/UMCS-93-8-1.ps.Z and I.J.Hayes, VDM and Z: A comparative case study, Formal Aspects of Computing, 4(1):76-99, 1992. VDM is discussed on the (unmoderated) VDM FORUM mailing list. Send a message containing the command "join vdm-forum " where is your real name to . To contact the list administrator, email John Fitzgerald at the University of Newcastle upon Tyne, England, on . Subject: What if I have spotted a mistake or an omission? Please send corrections or new relevant information about meetings, books, tools, etc., to . New questions and model answers are also gratefully received! -- Jonathan Bowen, Programming Research Group, Oxford University Computing Laboratory, UK.