Marek Sergot: A Memoir

This short memoir will recall some memories of Marek as a colleague, mentor, friend and external examiner. I first met Marek in the early eighties. I was working for the Department of Health and Social Security as part of a consortium funded under the Alvey program, which was designed to resurrect AI in the UK after the AI winter following the Lighthill report. We were supposed to apply expert systems techniques to large legislation based organisations. We were a motley crew of civil servants, programmers, soft systems analysts, sociologists, consultants and the man who had done the soldering on the first commercial computer built in the UK. Unfortunately, as a result of the AI winter, we knew little or nothing about AI, apart from that it was written in LISP. So we invited Imperial College to join us, and they sent us Marek and Bob Kowalski who told us that the way is should be done was to formalise the legislation in Prolog. An interesting five years were to follow. Bob and Marek made an interesting contrast. Bob was neat and rather contained, wearing a sports jacket and slacks, and speaking with authority but saying little. Marek, however, spilled out and filled the room. He was a big man in those days, with flowing locks and sweeping moustachois and invariably dressed in a short sleeved white shirt and signature blue cardigan. And he spoke a lot, with exuberance and optimism and good humour. The results of the project can be found in [1], which contains an excellent survey of AI and Law by Marek, and is available in all good antiquarian bookshops. After about six months I went to Imperial to work as an RA on that project. In those days 180 Queens Gate was a bit short on space, and I shared an office with Marek. This was a great privilege and an excellent introduction to the ways of academe. Not only did I get to see the master at work (although I never did get into the practice of drafting everything longhand), but I also was able to meet the succession of interesting people who came to visit Marek, and to sit quietly in a corner while he supervised his Masters and PhD students. Although I have no PhD in Computer Science I regard the three years of listening to these supervisions as more or less equivalent, with an excellent training is supervision thrown in for free. Marek’s patience and steady guidance provided an example which has stood me in good stead over the years. Another instance of Marek’s teaching skills stands out in my memory. The 1989 ICAIL was held in Vancouver, and on a free afternoon a group of us were in Stanley Park. Unable to find a bear for Marek to wrassle in the allegedly primordial forest, we found instead a par three golf course, and Marek, myself, Andrew Jones and Jon Bing formed a mixed ability foursome. On each of the first three holes I delivered a substantial hook which which would have sent the ball deep into the forest,if I had produced more power. As I was addressing the ball on the fourth tee, Marek suggested I alter my grip by turning my right hand through 45 degrees. To my surprise the ball went straight, and ever since then I have hit straighter than the post-scandal Tiger Woods, albeit typically only 10% as far. For me this sums up Marek’s teaching style: quiet observation of the problem unti it is fully understood; accurate identification of a solution; precise advice, quietly delivered; and then leaving the pupil to make the best of it. The other chief incident of the afternoon was Marek’s demonstration of his swing at full power: he lost his grip on the club and it sailed backwards over his head, travelling considerably further than the ball. With the Logic Programming Group at Imperial, Marek acted as a sort of Public Orator, and was normally called on to make the official speech at leaving presentations and the like. This was always done with taste and wit: I cannot honestly remember anything he actually said, even when the leaving do was mine, but I do remember that his speeches were thoroughly enjoyed and significantly increased the feel-good factor of the occasion, which is what matters. From the Imperial days I also remember Marek’s work for Charlotte-Anne software, which produced small expert systems which claimed to embody various aspects of the state of the art, such as object-oriented Prolog and the notorious Fuzzycalc R . Of course, these claims had to be taken cum grano salis, as we used to say, but I still remember the thrill that we felt the first time we read the message “fuzzy logic engine being unleashed ....... now!”. Charlotte Anne’s most successful deployment of Fuzzycalc R © was the popular Destination Advice For Travellers system. Its DAFT advice led to many satisfied holidaymakers. After I left Imperial to go to Liverpool, I saw less of Marek, meeting mainly at conferences. It was always good news if Marek was attending: the conference would be enhanced entertaining presentation, his astute but helpful questions, but most of all by his conversations in the breaks and after hours. Like the world of Wittgenstein’s happy man, a conference with Marek was bigger than one without him. For several years Marek was the external examiner for undergraduate degrees at Liverpool. This was very good for me as it became my duty and my joy to entertain him on the evening before the formal meeting.Each year we went to the same Chinese restaurant (Chinese was much better than Indian in Liverpool at the time) and ordered the banquet D as the simplest option including crispy duck. Our loyalty did the restaurant little good. Each time we returned there were fewer customers. On the last occasion we had the place to ourselves. It has now been closed for several years. Marek’s main contribution as external was to raise the aspirations (if not the standard) of our third year projects. Some of the more baroque features of our current project scheme can be traced back to the efforts made to achieve this. Of course, Marek was far from perfect. At least when I knew him, punctuality and productivity were two faults. If one had an arrangement to meet Marek, it was typically safe to arrive thirty minutes late, but a wait would still be probable. But if was usually necessary to wait for Marek, he was always worth waiting for. As for productivity, I asked him to supply the survey for [1] only because I knew it was already written. Even so it was the last contribution to arrive. When I telephoned him to ask how long it might be before I got it, he replied; “I have some good news and some bad news. The good news is that I put it in the post at 11.30. The bad news is that I took it out at 11.45 because I thought some of the round brackets should be square”. I best like to picture Marek holding forth in a bar at some conference somewhere, (perhaps the Bodeguita del Medio in Palo Alto at ICAIL 2007) and the whole group having a jolly time. Like Falstaff, Marek is “not only witty in himself, but the cause of wit in other men”. I was never in a company yet which was not the better for his presence.