Editorial: Monsieur Langlet’s Enterprise

VECTOR Vol.11 No.2

Editorial: Monsieur Langlet s Enterprise by Anthony Camacho

The philosophyof science is the study of how it is that we discover the truth about the world, and in particular those generaltruthsthat allow usto foresee, to someextent, the consequencesof our actions. Without such foresight morality is impossible since morality consists in acting so as to avoid doing harm. This showsthat knowledge is primary. The standard approachto the problem of discovering laws about the world is to try to guess at what might be a law and thentry to disproveit. If serious, well thoughtout attempts to disprove a hypothetical law havefailed to find fault then we may acceptit. Mostscientific experiments are involvedin these attempts to disprove a hypothesis.

The hypothesis is, of course, a model. It is a symbolic description of the world andcarries withit, in the meaning of its symbols, the clue to what tests would disproveit.

As I understand it Gérard Langlet, apart from his other work, suggests that, at the lowest level and thefinest detail, the way the world works must be simple. Complexity can only arise with structure and structureis built of parts which are combinations of the lowest level and finest details.

If the physical world is composed of quanta and timetoo is non-continuous then the models of the world which assume a continuum are inappropriate for dealing with quantised time and space.

Gérard suggests that, instead of forming our hypothetical models to match the world, we should build upstructures from the simplest possible elements bits. Whentheseare elaborated to the level where the real-world counterparts could be observed then wecan seek for such real world counterparts. A perfect match, that defies all attempts at disproof, between such a model and the real world would bea real breakthrough. J am not sure howclose the APL Theory of Human Vision gets: getting close enoughto consider the questionis exciting enough.

_ APL Preferences V

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MicroAPL Ltd., South Bank Technopark, 90 London Road, LONDONSE1 6LN, UK

Tel: 071 922 8866 Fax: 071 928 1006 Applelink: microapl Internet: microapl@applelink.apple.com

VECTOR Vol.14 No.2

Quick Reference Diary 1994 Date Venue Event

October 28th IEE BAA Meeting: Vendor Forum

June 4th-8th 1995 San Antonio, Texas APL95

British APL Association meetings are normally held in the IEE, Savoy Place. Nearesttube outlets: Temple or Embankment.

APL Training Courses for 1994

Level Company Days Dates

Intro APL MicroAPL 1 Nov 9

Intro APL2 MicroAPL 1 Oct 5, Nov 30

APL*PLUS MicroAPL 1 Nov 23

Advanced APL MicroAPL 1 Nov 16

APL GUI Design MicroAPL 4 Oct 19, Dec 14

Programming Techniques MicroAPL 1 Oct 26

If you would like to have your courses or seminars listed in Vector, please contact Gill Smith withthedetails.

Dates for Future Issues of VECTOR

Vol.11 Vol.i1 Vol.12 No.3 No4 No.1 Copy date 2nd Dec 94 3rd March 95 2nd June 95 Ad booking 9th Dec 94 10th March 95 9th June 95 Ad Copy 16th Dec 94 47th March 95 16th June 95 Distribution January 95 April 95 duly 95

APL Developers If you are an APL developer seeking a challenging and rewarding career opportunity, please consider joining our organization. SunGard Capital Markets (formerly Devon Systems International) is a world wide supplier of financial software for the derivatives market. Our company was founded in 1983 and our primary product is a trading support system for future, options, and interest rate products.

With over 500 clients world wide, the company and the product are well recognized as the leader in its field. The system is developed using Manugistics APL*Plus II and runs on most supported hardware platforms. We are currently undertaking a major effort to incorporate an SQL database and GUI front-ends using APL*Plus III, C++, MS Access and other new technologies. We are seeking experienced, motivated APL developers who are interested in real-world applications development. With SunGard Capital Markets, a unique opportunities exist to apply APL skills as well as to learn new technologies whilst serving a very sophisticated client base consisting of international banks and financial institutions.

Requirements for the position are a minimum of 3 years of APL development experience using APL*PLUS II or Dyalog APL. Familiarity with SYBASE (or other mainstream SQL), C or C++, Windows programming techniques and/or Windows-based software development environments such as Visual Basic or Microsoft Access would be a DEFINITE PLUS.

Salaries are highly competitive and relocation packages are available.

If you think you would be interested in this unique challenge, and would like to join our team of highly capable software developers in Philadelphia, please send your CV in confidence to:

SunGard Capital Markets Suite 900 510 Walnut Street Philadelphia, PA 19106 ATTN: Barbara Foley

VECTOR Vol.114 No.2

APL95 CALL FOR PARTICIPATION APL DoesIt Today SIGAPL s annualinternational conference for 1995 will take place between June 4 and June 8 in San Antonio, Texas. The technical themeof the conference is meant to emphasize practical use of APL. This breaks downinto two sub-themes:

+ APL95 as a showcasefor highly-successful use of APL in the real world

+ APL95 as a sourceof practical education in modern computing techniques using APL.

Of course, ourtechnical program will be opentoall forms of APL, J, and related languages, andtoall the traditional topics and formats of presentation but we will be placing special emphasis on material which relates to practical application. The key to a successful conference is effective publicity, and to make the publicity effective we need to include details of what will happen at APL95. That's why you'll see target dates includedin all the sections below. Some dates are very firm (paper review, for example, is a serious business that has to adhere to a schedule) others are morerelaxed. But the message aboutdatesis this: We can do moreto get a good audiencefor youif you let us know whatyou wantto do at APL95 in plenty of time.

The conference language is English; there will be no translation facilities at the conference and werequest thatall technical material be in English. However, we are more than happy to cooperate with prospective presenters who are not English speakers and will work with you on pre-conference translation of presentations.

Weinvite proposals from all APL practitioners for a presentation in any of the following formats:

VECTOR Vol.11 No.2

Tutorials and Workshops It's relatively easy for people to begin using APL; there are several companies whooffer introductory courses, and there are textbooks. But, once theinitial skills are achieved there are fewer resources for people to advance onto the next rung on the Jadder and becomecontributors of major value to their employers andclients.

The annual APL conferenceis a great concentrator of APLskills; indeedit s the oneeventof the year where nearly all the major players of APL will meet under one roof. At APL95 we wantto use them to their best advantage for practical, up- to-date and relevant training in the form of tutorials and workshops. One waythat you canhelp us with this is to offer to lead a tutorial or workshop session on the topic of your choice. Someof the things that we havein mind are: - Event-driven applications programming - Object-oriented programming - Large APL applications (high code volumeor high data volume)

Youwill certainly be able to think of others.

Another way you can helpus is bytelling us the tutorial and workshop topics which would make APL95irresistible to you as a delegate. If enough people say they would attend a session on a particular subject, we'll do everything we can to get the best possible presenters. Please let us have your tutorial and workshop proposals by January 1, 1995.

Reviewed Papers Reviewed papers have long been the backboneof the conference, and we intend this to continue. We invite original technical papers onall aspects of APL. These papers will be subject to double-blind peer review, and those whichare selected for presentation will be printed in the APL95 Conference Proceedings, which will be an issue of APL Quote Quad distributed to the conference delegates, SIGAPL members andlibraries world-wide.

In order for us to begin to structure the technical program we would like prospective authors to sendtitle(s) and/or abstract(s) to us as quickly as possible (preferably before November 1, 1994).

Draft papers for review must be received no later than December 1, 1994; you may send a draft paper even though you have notsenta title or abstract earlier than this. Draft papers shouldnot exceed 6,000 words.

VECTOR Vol.11 No.2

Informal Posters Poster sessions are becoming increasingly important at SIGAPL s conferences; wewill continue to build this aspect of the program at APL95.

Posters are a great way to present your ideas informally and receive feedback from an interested audience. In order to maximize the impact of posters we would like you to submit your proposals in advance of the conference although you mayjust turn upat the conference with a posterif you prefer.

Theonly restrictions on the format of a poster are thatit fit onto a metre-square wall area, must be original work, and that it must be a technical presentation (advertisers are expected to book space in APL95 s exhibit area). Posters are not subject to peer review. We invite poster presenters to prepare a one-page summary of the ideas in their poster which may be distributed during their poster session; in addition, we maybeable to find room for poster summaries in future editions of Quote Quad.

Weare happyto receive advance poster submissions until May 1, 1995.

Panel Discussions Whatare the hot topics for APL in 1995? How does APL fit in with the ever- changing outside world? Panels have always been the format we choose to explore these topics, and we see panels as an important part of being at APL95 rather than reading aboutit later. Someof the things we already know we want to explore in panel sessionsare:

- The reunification of APL - Which paradigmsof the outside world are passing fads, and which should we absorb into APL?

No doubt you can think of more. We want to hear from you because a well- prepared panelhas far more value than one whichis producedlate in the day. We'd like your panel proposals by January 1, 1995.

Software Exchange SIGAPL invites you to send new and useful APL/J software to the APL95 Software Exchange. New GUI software is especially welcome. Software from prior APLconferencesis also welcomeif it s been significantly improved. APLS5 conference software will be available in three ways:

VECTOR Vol.11 No.2

1 The Conference Package: software received by April 5, 1995 will be available for purchase at APL95 in San Antonio.

2 The APL95 Supplement: software received between April 5 and June 8, 1995 will be mailed at no chargeto all who purchase the Conference Packageat APL95. 3 The Conference Package, plus the APL95 Supplement above, will be available by about October 1995 from SIGAPL, the BBS\APL, and the Waterloo archive.

Send software for the APL95 Software Exchangeon a 3.5"disk to:

Dick Holt, 3802 N. RichmondSt,, Arlington VA 22207, USA

Software in APL, J, and related languages is invited. English is preferred, but other languages are also welcome. Your material should include an ASCII file that briefly describes what the software does, and what other software/hardware is needed to use it. Please include permission to distribute any copyright software.

Other What have we forgotten? APL95 is wide opentoall of your ideas whether you are a SIGAPL memberor not(and if you're not we'll be very happy to tell you how you can becomeone). If there s a topic that you'd like to be a part of APL95 that you haven't seen above let us know, and we'll do all we can tofit it in.

If there s a way you want to present your ideas that doesn t fit into these categories let us know that as well.

Above all, APL95 is going to be YOUR conference. The Organizing Committee and the Program Committee are here to turn your ideas into reality we look forward to your responses!

Contact Information Two Internet distribution lists have been set up for APL95. APL95_info@ACM.org will be used for broadcasting information to the subscribers. To subscribe, just send a one-line message to mailserv@ACM.org ; that single line should tread subscribe APL95_info your_e-mail_address . The otherlist is APL95_conf@ACM.org , to be usedforinitiating conversations with APL95 Committee members. Someone will reply to your message as soon as possible.

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VECTOR Vol.11 No.2

Site Information San Antonio boasts a variety of attractions, from international shopping and dining along the tree-shaded Riverwalk to the historic Alamo, where a band of 189 Texan volunteers defied an army of thousandsin 1836. The flavour of old Texas is everywhere. Stroll through the narrow streets and shaded patios of La Villita, a restored Mexican village. Shop for handicrafts and farm-fresh produce at the colourfulstalls of El Mercado. Relive the Old Westat the Cowboy Museum. Enjoy exhibits of contemporary Mexican artists at the Mexican CulturalInstitute. Even the giant new amusementpark Fiesta Texas has a distinctive Texasflavor. Ride the Dining Train, tour art museums, or spend the day at Hemisfair Park, site of the 1968 World s Fair. Go back in time to the missions of San Antonio. Buy a cowboy hat and bring sun-screen; the weather will be hot and dry....YEE HA!

Get yourself and yourinterests registered! Please complete and mailthe enclosed form to:

APL95, P.O. Box 210367, Bedford, TX 76095 USA

1

dyalogVAFB)] The Definitive APL for Windows

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Experience counts Since we launched Dyalog APL/W at APL92, nearly two years ahead of our nearest competitor, our customers have developed hundredsofsuccessful industrial-strength GUI applications. With the benefit of their experience, we have enhanced and refined Dyalog APL/W into the mature, stable and above all useful Windows developmenttool that it is today.

Not only does Dyalog APL/W provide the most comprehensive set of GUIfacilities available for any APL, but you can be confident that your workspaces will run unchanged on Unix workstations under OSF/Motif.

With Version 7.0 we have added support for Visual Basic Custom Controls, a powerful built-in Grid object, Numeric, Currency, and Date fields, ToolBar, StatusBar and TabBar objects, automatic context-sensitive Hints and Tips, Metafiles, MDI, 3-D Forms and Controls, a fully customisable Session, an ODBC interface, Namespaces for encapsulation, and a host of other improvements.

That's why Dyalog APL/W remainsthe professional choice. Fora free trial copy, contact Dyadic or yourlocal distributor today.

Dyadic Systems Limited., Riverside View, Basing Road, Old Basing, Basingstoke, Hants RG24 7AL, United Kingdom. Tel:(0256) 811125 Fax: (0256) 811130 Email: sales@dyadic.com.

VECTOR Vol.11 No.2

Newsfrom Sustaining Members Compiled by Gill Smith

Dyadic Systems Ltd Dyadic is extremely pleased with the way the new version of Dyalog APL was received at APL94. Delegates who attended Dyadic s Vendor Forum (and most did) heard John Scholes give the first presentation of Namespaces outside the UK. The reaction from the audience, most of whom were unawareof this new development, was extremely positive.

Namespacesallow you to organise your functions and variables into logical units and sub-systems, just as the DOS. directory structureallows you to organise your files. In Dyalog APL, the active workspace is also knownas the root namespace; ratherlike the root directory in DOS. Objects that you create at this level are held in the root namespace,justlike files in your root directory. (If you don t want to use namespaces, you candefine all of your objects in the root namespace, just as before.) However, you can also create a namespace (analogous to a sub- directory) in which you can place other objects and indeed other namespaces. There is no limit to the number of namespaces you can have, nor to the depth they are nested.

Namespaces do not just allow you to organise your workspacebetter, they also act as different contexts for the execution of code. When a function runs in a namespace, the namesof variables and other functions to whichit refers are local to that namespace, and do notconflict with objects with the same namesin other namespacesor in the outer workspace. This meansthat,for the first time in APL, you can write a self-contained utility or a complete application that can safely be copied into any other workspace and run without fear of name conflicts. Namespaces also make it extremely easy to implement large application workspaces that contain logically separate sub-systems, without the need to resort to overlay files and similar techniques.

Namespaces providebenefits to all APL developers, but are of particular appeal to those developing GUI applications. This is because GUI objects (Forms, Buttons, Grids and so forth) are also namespaces themselves. This means that you can store all of the callback functions, and any data variables that they require, inside the object to which they apply, rather than having them swill around in the workspace. Namespaces provide a much needed solution for the requirement to pass information between callback functions, and between

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VECTOR Vol.11 No.2

successive invocations of the samecallback, without the use of global variables (ie. variables that are global to the workspace as a whole). Instead, such variables becomestatic variables, that are local to an object (and thus directly accessible from functions running within that object) but do not pollute the workspace as a whole. Furthermore, as GUI objects are namespaces, you can write a completely self-contained GUI widget that containsall the required APL code and data, together with its GU] components, and save it as a single object that can subsequently be copied into any active workspace and run. The user sees only whatthe object does; not how it doesit, a fundamental tenet of object- oriented programming.

Dyadic intends to use namespacesasthe basis of further development towards object-oriented programming, and to provide the advantages (but not the complexities) of this approach for Dyalog APLusers in the future.

Insight Systems So far, the secondhalf of 1994 hasleft us breathless. After announcing SQAPLfor SequeLink at APL93 in Toronto, we slowly sold about a dozen evaluation systems during the next twelve months. A yearlater, many of these customers are buying 20- to 50-user production systems.Thefirst five beta copies of SQAPL 2.0 with ODBC support went to new customers in Helsinki, London, Melbourne, New York, and Rio de Janeiro. New customers are queuing up, and redistribution agreements are now more orless in place with three major APL vendors. The rumours regarding the death of APL seem to be premature, and the non-APL middleware market seemsto be takingoff like a rocket too, so we have never beenbusier.

Dyadic shipped SQAPL/EL with version 7 of Dyalog APL for Windows. The Entry Level version contains all the functionality required to get started with simple ODBC drivers for local databases such as dBase or Access. By the time this is printed, we should have completed the Professional Edition, which contains a number of additional features to increase programmer productivity, and take advantage of performance options in advanced ODBCdrivers, especially when using remote databases. We are now concentrating on assisting Manugistics in the packaging of both the /EL and /PE versions of SQAPL for APL*PLUSII], and working with Soliton to provide SQAPL for Sharp APL under Unix. We will also provide a version of /PE for J version 2 from Iverson Software, so you can get started on J using a familiar tool for database access. Upon demand,wewill make the tool (SQJ?) available for J under OS/2 and Unix, too. Need a copy of SQK?Please call us!

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VECTOR Vol.11 No.2

A second generation of servers, based on SequeLink version 2.5, will provide ODBC access to Unix APL servers (and hopefully also APL2 under MVS) by the end of the year. Weare also starting work on a local ODBC driver for APL, which will give direct access to Dyalog APL/W and APL*PLUSIII without the use of middleware. This productwill also be available before yearend,if all goes well (we needit for a project of our own before that).

The idea of an ODBCdriver for a local or remote APL interpreter may seem bit strange. ODBC is for SQL databases, and the most natural way to call a developmenttool like APL under Windows would be via DDE or as a DLL? There are dozens of APL applications containing their own databases, which suffer from the fact that their internal databases are inaccessible to mainstream tools. With our ODBC APLdrivers, we will provide tools to help you write simple SQL interpreters, so you canlet people go into Microsoft Access, connect to APL (which you sold as a high-performance multi-dimensional DBMS) and say:

select high, low, close from currdb where market='NYC' and currency='!JPY' and date>19940101 and frequency='WEEKLY' and totalling='AVERAGES'

Although the underlying database may be a four-dimensional table with daily rates, we can return a two-dimensional table with massaged data, pretending that we have an SQL table containing weekly averages. This idea can be extended to all kinds of analyses so APL can contain infinitely large SQL tables. The ultimate virtual database is the one whichallows queries like: select result from ap! where expression='2+2!

Once more, a changeof Internet address. Our address is now insight@inet.uni- c.dk.

Manugistics Inc Manugistics released version 1.2 of APL*PLUSIII for Windowsalmost a week ahead of schedule. We feel this version further positions APL*PLUS If as the strategic choice for Windows development. Major enhancements found in this release include support for Visual Basic Custom Controls, calling 16-bit DLLs directly, new object classes for MDI application development and more contro! structures; including :continue,:leave and :goto.

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VECTOR Vol.11 No.2

Currently, there are several beta sites testing the ODBC interface developed by Insight Systems for APL*PLUSIII. Reports so far have been very positive and we soon hopeto simultaneously release two versions of the product one designed specifically for the single/ad-hoc user, the other designed for the commercial APL developer who needs to provide an ODBC enabled product with more functionality. For more information on ODBC for APL*PLUSII], please contact Manugistics, Insight Systems or your local APL*PLUSdealer.

The Manugistics troop returned safe and sound from APL94.In keeping with the conference theme of The Language and its Applications , a commercial application developed in APL*PLUS III by GEIS called LEX2000 was presented during our vendor forum along with demonstrations of using VBXs and ODBC. Our software drawing winner was Daniel Jonusz of Mobil Oil Corporation in Princeton, NJ and APL*PLUS Sport Radios were wonby three other conference attendees.

Avery exciting synergy is developing between our mainframe based enterprise- wide planning product and the APL*PLUS Network Sharefile product. Two new sites began using Network Sharefile in the past few weeks with more to come. Network Sharefile allows multiple copies of the APL*PLUSSharefile system to communicate with one another. A user can be running an application that appearsto be using one Sharefile database while a numberof Sharefile databases in virtually any location may actually be in use. The benefits of Network Sharefile include better performance andbetter data security and integrity.

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The Education Vector Vol.11 No.2

THE EDUCATION VECTOR October 1994

Editor Ian Clark This Education Vector has been reprinted from VECTOR Vol.11 No.2. VECTOR is the Quarterly Journal of the British APL Association. For more information aboutthe British APL Association, please contact: Anthony Camacho, 11 Auburn Rd, Redland, BRISTOL, BS6 6LS Tel: 0272-730036.

Contents Editorial Tan Clark 18

Jot-Dot-Floor Jan Clark 20 J-ottings 3 Norman Thomson 24 J: Bibliography Donald B. McIntyre 28 Cowsand Bulls - A Solution Anne Wilson 29 More about Fractional Series J.R. Sutton 30

Ian Clark IAC/HumanInterfaces, 9, Hill End, Frosterley, Bishop Auckland, Co. Durham DL13 28x.

Tel: 0388-527190 Email: clark.i@applelink.apple.com or 100021.3073@compuserve.com

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The Education Vector Vol.11 No.2

Editorial by Ian Clark

Welcometo another edition of Education VECTOR.This goesto press just before APL 94, so whatever enlightenment emerges during the symposium will just haveto wait for the next issue.

A teacherfriend I saw recently congratulated herself on getting through thefirst week of term. Her face wasn t grey and the lines on it were fading (I thought) so she must have had a good summerholiday. With the unions all set to continue their boycott of the compulsory testing of the National Curriculum and the Governmentstill striving to re-introducethe eleven-plus in one form or another, with amateur markers to swell the ranks of amateur inspectors, no doubt all riding to work on trains directed by amateur volunteer signalmen, this has got to be the Golden Age of the Amateur Volunteer.

Nowhereis this more evident than the teaching of Mathematics. A recent report on the sorry state of mathematics teaching seemsto lay the blame squarely on Primary Schools. Primary teachers might justifiably wonder what it is the country really wants of them. To be the saviours of the next generation? Or to serve as whipping boysfor the undesirable side-effects of a society governed by marketforces and other gods of darkness? If mathematical skills are to be costed on their current market value by sector,is it any surprise that they re tending to accumulate in the faster end ofthe financial sector and desert the junior end (and upwards)of the educational sector?

For years those further up the educational tree have been telling the primary schools thatall they require of them are children able to go to thetoilet without supervision, tie their own shoelaces and write their own names. Leavethe fancy stuff to those better qualified to teach it. Now it emerges that primary teachers have to carry the can back for the state of Mathematics throughoutthe entire system.

This isn t the place to discuss the role of specialist teaching in primary schools. Nor the evidence for and against the existence of things called pre-mathematical skills. But I do think that those responsible for the staffing and remuneration of schools should not hide from criticism behind the honest attempts of others to putinto effect the results of their own loose thinking. I rememberseeing a report, at least six or seven years ago now, aboutthe teaching of Mathematics in both primary and secondary schools in England and Wales. It furnished figures to

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The Education Vector Vol.i1 No.2

show that at least 70% of mathematics teachers had no recognisable qualifications in mathematics beyond O-level, and that perhaps 90% were teaching the subject far abovethe level at which they were technically qualified.

Now never mind the reasons for this state of affairs and why it cannot be otherwise. Never mind asking whether they are doing a good job. Never mind wondering how to compel them to do a better one, by performancerelated pay, say, or testing their pupils at frequent intervals with nationwide tests, The question we wantto ask ourselves is no, not whether we're feeling lucky, but whether we would tolerate such a situation in the teaching of French, say, or Spanish.

Now I have a shameful admission to make. | hardly know a word of Spanish (except one or two I learnt from reading Hemingway, which it seems I don t pronounce correctly anyway). Yet, if Spanish were to be treated as Mathematics is at present, I could be recruited to teach PE, RE or any other E for which I mightbe qualified, then directed to teach Spanish throughoutthe school. Would any blameattach to meif someofficial Spaniard came along and castigated my teaching(1 think that s the word)? In a fair and just society, notatall. The blame would lie with the headmaster, or rather with those who made upthe rules which forced the headmaster to contemplate such a ludicrous step. And ultimately, in a democracy,that s all of us. The headmaster might turn round and say he couldn t get anyone whoreally knew Spanish for love or money. Market forces, again. But what a slur on our society, and those wholeadit.

The governmenthave showntime and again in other spheres thatit is possible to manipulate marketforces. In fact they've spentbillions doing so. Let them do so in the sphere of Mathematics teaching, if we all agree it s so important for the future economic health of the country.

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