Guerrilla logic: a salute to Mervyn Pragnell

When a detailed history of computer science in Britain comes to be written, one name that should not be forgotten is Mervyn O. Pragnell.  As far as I am aware, Mervyn Pragnell never held any academic post and he published no research papers.   However, he introduced several of the key players in British computer science to one another, and as importantly, to the lambda calculus of Alonzo Church (Hodges 2001).  At a time (the 1950s and 1960s) when logic was not held in much favour in either philosophy or pure mathematics, and before it became to be regarded highly in computer science, he studied the discipline not as a salaried academic in a university, but in a private reading-circle of his own creation, almost as a guerrilla activity.

Pragnell recruited people for his logic reading-circle by haunting London bookshops, approaching people he saw buying logic texts (Bornat 2009).  Among those he recruited to the circle were later-famous computer pioneers such as Rod Burstall, Peter Landin (1930-2009) and Christopher Strachey (1916-1975).  The meetings were held after hours, usually in Birkbeck College, University of London, without the knowledge or permission of the college authorities (Burstall 2000).  Some were held or continued in the neighbouring pub, The Duke of Marlborough.  It seems that Pragnell was employed for a time in the 1960s as a private research assistant for Strachey, working from Strachey’s house (Burstall 2000).   By the 1980s, he was apparently a regular attendee at the seminars on logic programming held at the Department of Computing in Imperial College, London, then (and still) one of the great research centres for the application of formal logic in computer science.

Pragnell’s key role in early theoretical computer science is sadly under-recognized.   Donald MacKenzie’s fascinating history and sociology of automated theorem proving, for example, mentions Pragnell in the text (MacKenzie 2001, p. 273), but manages to omit his name from the index.  Other than this, the only references I can find to his contributions are in the obituaries and personal recollections of other people.  I welcome any other information anyone can provide.

UPDATE (2009-09-23): Today’s issue of The Guardian newspaper has an obituary for theoretical computer scientist Peter Landin (1930-2009), which mentions Mervyn Pragnell.

UPDATE (2012-01-30):  MOP appears also to have been part of a production of the play The Way Out at The Little Theatre, Bristol in 1945-46, according to this web-chive of theatrical info.

UPDATE (2013-02-11):  In this 2001 lecture by Peter Landin at the Science Museum, Landin mentions first meeting Mervyn Pragnell in a cafe in Sheffield, and then talks about his participation in Pragnell’s London reading group (from about minute 21:50).

UPDATE (2019-07-05): I have learnt some further information from a cousin of Mervyn Pragnell, Ms Susan Miles.  From her, I understand that MOP’s mother died in the Influenza Pandemic around 1918, when he was very young, and he was subsequently raised in Cardiff in the large family of a cousin of his mother’s, the Miles family.  MOP’s father’s family had a specialist paint manufacturing business in Bristol, Oliver Pragnell & Company Limited, which operated from 25-27 Broadmead.  This establishment suffered serious bomb damage during WW II.   MOP was married to Margaret and although they themselves had no children, they kept in close contact with their relatives.  Both are remembered fondly by their family.   (I am most grateful to Susan Miles, daughter of Mervyn Miles whose parents raised MOP, for sharing this information.)

References:

Richard Bornat [2009]:  Peter Landin:  a computer scientist who inspired a generation, 5th June 1930 – 3rd June 2009.  Formal Aspects of Computing, 21 (5):  393-395.

Rod Burstall [2000]:  Christopher Strachey – understanding programming languages.  Higher-Order and Symbolic Computation, 13:  51-55.

Wilfrid Hodges [2001]:  A history of British logic.  Unpublished slide presentation.  Available from his website.

Peter Landin [2002]:  Rod Burstall:  a personal note. Formal Aspects of Computing, 13:  195.

Donald MacKenzie [2001]:  Mechanizing Proof:  Computing, Risk, and Trust.  Cambridge, MA, USA:  MIT Press.

Alan Turing

Yesterday, I reported on the restoration of the world’s oldest, still-working modern computer.  Last night, British Prime Minister Gordon Brown apologized for the country’s treatment of Alan Turing, computer pioneer.  In the words of Brown’s statement:

Turing was a quite brilliant mathematician, most famous for his work on breaking the German Enigma codes. It is no exaggeration to say that, without his outstanding contribution, the history of World War Two could well have been very different. He truly was one of those individuals we can point to whose unique contribution helped to turn the tide of war. The debt of gratitude he is owed makes it all the more horrifying, therefore, that he was treated so inhumanely. In 1952, he was convicted of ‘gross indecency’ – in effect, tried for being gay. His sentence – and he was faced with the miserable choice of this or prison – was chemical castration by a series of injections of female hormones. He took his own life just two years later.”

It might be considered that this apology required no courage of Brown.

This is not the case.  Until very recently, and perhaps still today, there were people who disparaged and belittled Turing’s contribution to computer science and computer engineering.  The conventional academic wisdom is that he was only good at the abstract theory and at the formal mathematizing (as in his “schoolboy essay” proposing a test to distinguish human from machine interlocuters), and not good for anything practical.   This belief is false.  As the philosopher and historian  B. Jack Copeland has shown, Turing was actively and intimately involved in the design and construction work (mechanical & electrical) of creating the machines developed at Bletchley Park during WWII, the computing machines which enabled Britain to crack the communications codes used by the Germans.

Turing-2004-Poster

Perhaps, like myself, you imagine this revision to conventional wisdom would be uncontroversial.  Sadly, not.  On 5 June 2004, I attended a symposium in Cottonopolis to commemorate the 50th anniversary of Turing’s death.  At this symposium, Copeland played a recording of an oral-history interview with engineer Tom Kilburn (1921-2001), first head of the first Department of Computer Science in Britain (at the University of Manchester), and also one of the pioneers of modern computing.   Kilburn and Turing had worked together in Manchester after WW II.  The audience heard Kilburn stress to his interviewer that what he learnt from Turing about the design and creation of computers was all high-level (ie, abstract) and not very much, indeed only about 30 minutes worth of conversation.  Copeland then produced evidence (from signing-in books) that Kilburn had attended a restricted, invitation-only, multi-week, full-time course on the design and engineering of computers which Turing had presented at the National Physical Laboratories shortly after the end of WW II, a course organized by the British Ministry of Defence to share some of the learnings of the Bletchley Park people in designing, building and operating computers.   If Turing had so little of practical relevance to contribute to Kilburn’s work, why then, one wonders, would Kilburn have turned up each day to his course.

That these issues were still fresh in the minds of some people was shown by the Q&A session at the end of Copeland’s presentation.  Several elderly members of the audience, clearly supporters of Kilburn, took strident and emotive issue with Copeland’s argument, with one of them even claiming that Turing had contributed nothing to the development of computing.   I repeat: this took place in Manchester 50 years after Turing’s death!    Clearly there were people who did not like Turing, or in some way had been offended by him, and who were still extremely upset about it half a century later.  They were still trying to belittle his contribution and his practical skills, despite the factual evidence to the contrary.

I applaud Gordon Brown’s courage in officially apologizing to Alan Turing, an apology which at least ensures the historical record is set straight for what our modern society owes this man.

POSTSCRIPT #1 (2009-10-01): The year 2012 will be a centenary year of celebration of Alan Turing.

POSTSCRIPT #2 (2011-11-18):  It should also be noted, concerning Mr Brown’s statement, that Turing died from eating an apple laced with cyanide.  He was apparently in the habit of eating an apple each day.   These two facts are not, by themselves, sufficient evidence to support a claim that he took his own life.

POSTSCRIPT #3 (2013-02-15):  I am not the only person to have questioned the coroner’s official verdict that Turing committed suicide.    The BBC reports that Jack Copeland notes that the police never actually tested the apple found beside Turing’s body for traces of cyanide, so it is quite possible it had no traces.     The possibility remains that he died from an accidental inhalation of cyanide or that he was deliberately poisoned.   Given the evidence, the only rational verdict is an open one.

Saving Kim Dae-jung

One event that always intrigued me about the life of Kim Dae-Jung was his release by the Korean CIA after their kidnap and torture of him in 1973, a release apparently forced on the Koreans by the US Government.  Such concern for the human rights of opposition dissidents in US-allied countries always struck me as very uncharacteristic of the brutal and cynical real-politic, bordering on madness,  of the Nixon-Kissinger White House, and I always wondered what prompted the concern on that particular occasion.  Now we learn from an op-ed article in the International Herald Tribune that Nixon and Kissinger knew little or nothing about the pressure their administration brought to bear on the repulsive Park regime to release Kim unharmed.  That pressure, which was intense and concerted, was the work of two brave US Government officials, State Department Korea expert Donald L. Ranard and then US Ambassador to the Republic of Korea, Philip Habib.
Reference:
Donald A. Ranard [2009-08-25]:  Saving Kim Dae-jung.  International Herald Tribune, page 6.  For reasons known only to themselves, and as further evidence of the MSM’s failure to understand the 21st century, this article appears not to be in the New York Times online archive (at least, it is not accessible via its title, its author, or any of the people mentioned in it!) 
Postscript (added 2010-08-09):  Here is the article on the site of The Boston Globe.

Kim Dae-Jung RIP

The death has just occurred of Kim Dae-Jung (1924-2009), brave Korean dissident and opposition leader, who later became President.  The Guardian’s obituary is here.   He survived imprisonment, a death sentence, a kidnap and beatings by the Korean Central Intelligence Agency, speaking out bravely and persistently against the ruthless Park and Chun dictatorships to become the Republic of Korea’s first non-Conservative President.   However, the military-jaebol complex which has run the country since WW II proved too strong for him, and he was not able to enact the reforms he desired.  His strong desire for peace and possibly unification of the two Korean states may also have led him to a certain naivety in dealings with the criminal gang who enslave the North.
The Guardian has a photo gallery of the life of Kim Dae-jung here.

A salute to Flo Skelly

Watching Season 2 of Mad Men with its arc of the rise of a female copywriter (Peggy Olsen, played by Elisabeth Moss), I was reminded of that real pioneer woman in advertising, Florence Skelly, who died in 1998 aged 73.  I never had the good fortune to work with her, but I have worked with lots of people who did.  The stories about her were legion.    I recall especially hearing about a series of detailed presentations she gave in the mid-1990s on the attitudes and aspirations of teenagers — those in what we would now call late GenX and early GenY — a group she seemed to know better than any other researcher around.   The irony was that she herself was at the cusp of her eighth decade!
Interestingly, season 1 of Mad Men had a couple of scenes involving market researchers, but the one woman was a PhD psychologist with a Central European accent, apparently unable to be creative and clearly instantiating a different (albeit then-common) archetype to Flo Skelly.
On Mad Men,  a reminder that Ta-Nehisi Coates, mashing Karl Rove, last October captured the demographic of the typical viewer with great precision:

Even if I’ve never met you, I know you all. You guys are that dude at the country club with the beautiful date, holding a martini and a cigarette, standing against the wall and making snide comments about all the CSI-viewers who pass by. And you’re also a Muslim. Can’t forget Muslim.

A salute to Thomas Harriott

Thomas Harriott (c. 1560-1621) was an English mathematician, navigator, explorer, linguist, writer, and astronomer.  As was the case at that time, he worked in various branches of physics and chemistry, and he was probably the first modern European to learn a native American language.  (As far as I have been able to discover, this language was Pamlico (Carolinian Algonquian), a member of the Eastern Algonquian sub-family, now sadly extinct.)  He was among those brave sailors and scientists who traversed the Atlantic, in at least one journey in 1585-1586, during the early days of the modern European settlement of North America.  Because of his mathematical and navigational skills, he was employed variously by Sir Walter Raleigh and by Henry Percy, 9th Earl of Northumberland, both of whom were rumoured to have interests in the occult and in the hermetic sciences.   Harriott was the first person to use a symbol to represent the less-than relationship (“<“), a feat which may seem trivial, until you realize this was not something that Babylonian, Egyptian, Greek, Islamic, Indian, or Chinese mathematicians ever did; none of these cultures were slouches, mathematically.
Yesterday, 26 July 2009, was the 400th anniversary of Harriott’s drawing of the moon using a telescope, the first such drawing known.  In doing this, he beat Galileo Galilei by a year.   The Observer newspaper yesterday honoured him with a brief editorial.
Interestingly, Harriott was born about the same year as the poet Robert Southwell, although I don’t know if they ever met.     Southwell spent most of his teenage years and early adulthood abroad, and upon his return to England was either living in hiding or in prison.  So a meeting between the two was probably unlikely.  But they would have each known of each other.
Previous posts  in this series are here.   An index to posts about the Matherati is here.

4 June 1989

Today is the 20th anniversary of the election of the first democratic non-Communist Government in Poland after WW II, the event which presaged the later changes throughout Eastern Europe and the USSR of that revolutionary year.
Today is also the 20th anniversary of the brutal and unprovoked massacre of the student protesters in Tiananmen Square, Beijing, by the PLA, under the illegal orders of Deng Xiaopeng and his henchmen.  Only the brave Zhao Zhiyang, then General Secretary of the Communist Party of China, and Hu Qili, then a Politburo Standing Committee member, argued against Deng’s decision to impose martial law within the ruling party internal discussions.
This post honours the heroes who died or were imprisoned in that period.   Previous posts in this series are here.
References:

A. J. Nathan and P. Link (Editors) [2001]: The Tiananmen Papers. Compiled by Zhang Liang, with an afterword by O. Schell. (Little, Brown and Company, London, UK.)

Ziyang Zhao [2009]: Prisoner of the State: The Secret Journal of Premier Zhao Ziyang. Edited by Adi Ignatius. Foreword by Roderick MacFarquhar.  Translated and edited by Bao Pu and Renee Chiang. (Simon & Schuster, New York, USA.)

At the hot gates: a salute to Nate Fick

After viewing The Wire, certainly the best television series I have ever seen (and perhaps the best ever made), I naturally sought out Generation Kill, from the same writing team – David Simons and Ed Burns.  Also gripping and intelligent viewing, although (unlike The Wire), we only see one side’s view of the conflict.   The series follows a US Marine platoon, Second Platoon of Bravo Company of the 1st  Reconnaissance  Battalion, 1st Marine Regiment, as they invade Iraq in March-April 2003.   Like Band of Brothers, we come to know the platoon and its members very well, feeling joy at their wins, and sorrow at their losses.  The TV series is based on an eponymous 2004 book by a journalist, Evan Wright, who was embedded with the platoon in this campaign.
The TV series led me, however,  to read another book about this platoon, written by its commanding officer Lt. Nathaniel Fick (played in the series by actor Stark Sands).    The book is superb!    Fick writes extremely well, intelligently and evocatively, of his training and his battle experiences.  His prose style is direct and uncluttered, without being a parody of itself (as is, say, Hemingway’s).  His writing is remarkably smooth, gliding along, and this aspect reminded me of Doris Lessing, on one of her good days.   Fick clearly has a firm moral centre (perhaps an outcome of his Jesuit high school education), evident from his initial decision to apply to the military while still an undergraduate classics major at Dartmouth.     Having felt a similarly-strong desire as an undergraduate to experience life at the hot gates, I empathized immensely with his description of himself at that time.   Fick’s moral grounding is shown throughout the book, not only in the decisions he takes in battle, and his reflections on these decisions, but also in the way he refrains from naming those of his commanding officers whom he does not respect.    He also shows enormous loyalty to the men he commanded.
And Fick’s experiences demonstrate again that no organization, not even military forces,  can succeed for very long when commands are only obeyed mindlessly.   Successfully execution of commands requires intelligent dialogue between commanders and recipients, in a process of argumentation, to ensure that uttered commands are actionable, appropriate, feasible, effective, consistent, ethical and advisable.  Consequently, the most interesting features of the book for me were the descriptions of decision-making, descriptions often implicit.   Officers and non-officers, it seems, are drilled, through hours of rote learning, in the checklists and guiding principles necessary for low-level, tactical decision-making, so that these decisions can be automatic.  Only after these mindless drills are second nature are trainee officers led to reflect on the wider (strategic and ethical) aspects of decisions,  of decision-making and of actions.   I wonder to what extent such an approach would work in business, where most decision-making, even the most ordinary and tactical, is acquired through direct experience and not usually taught as drills.  Mainly this is because we lack codification of low-level decision-making, although strong fmcg companies such as Mars or Unilever come closest to codification of tactical decision-making.
Fick’s frequent frustrations with the commands issued to him seem to arise because these commands often ignore basic tactical constraints (such as the area of impact of weapons or the direction of firing of weapons), and because they often seem to be driven by a concern for appearances over substantive outcomes.   In contrast to this frustration, one of Fick’s commanding heroes is Major Richard Whitmer, whose unorthodox managerial style and keen intelligence is well described.  A military force able to accommodate such a style is to be admired, so I hope it is not a reflection on the USMC that Whitmer appears to have spent the years since the Iraq invasion running a marine recruitment office.  Next time that I’m CEO of a Fortune 500 company, I’ll actively try to recruit Whitmer and Fick, since they are both clearly superb managers.
I was also struck by how little the troops on the ground in Iraq knew of the larger, strategic picture.  Fick’s team relied on broadcasts from the BBC World Service on a personal, non-military-issue transister radio to learn what was happening as they invaded Iraq.   We who were not involved in the war also relied on the BBC, particularly Mark Urban’s fascinating daily strategic analyses on BBC TV’s Newsnight.  Were we remote viewers better informed than those in the ground in Iraq?  Quite possibly.
Nathaniel Fick now works for a defence think tank, the Center for a New American Security.  A 2006 speech he gave at the Pritzer Military Library in Chicago can be seen here.   A seminar talk to Johns Hopkins University’s series on Rethinking the Future Nature of Competition and Conflict can be found here (scroll down to 2006-01-25).  And here is Fick’s take on recent war poetry.
References:
K. Atkinson et al. [2008]: Command dialogues. In: I. Rahwan and P. Moraitis (Editors): Proceedings of the Fifth International Workshop on Argumentation in Multi-Agent Systems (ArgMAS 2008), AAMAS 2008, Lisbon, Portugal.
Nathaniel Fick [2005]:  One Bullet Away:  The Making of a Marine Officer.  London, UK:  Phoenix.
Evan Wright [2004]:  Generation Kill. Putnam.

A salute to Zdenek Mlynar

Continuing our series of heroes, I would like to honour Zdenek Mlynar (1931-1997).  Mlynar was an idealistic Czech communist who, as the principal author of the Action Programme of the Czechoslovak Communist Party (KSC), was the key theoretician of the Prague Spring in 1968.  Mlynar had earlier been selected by the party to study Marxist theory and law in Moscow in the 1950s, where he was a fellow student and friend of another young, idealistic communist, Mikhail Gorbachev.   Upon his return to the CSSR, Mlynar worked within the KSC to increase democracy, both internally within the party and in public life, becoming one of the reformers around Alexander Dubcek in the mid 1960s.

After the invasion of the CSSR by forces of the Warsaw Pact in 1968, Mlynar refused to submit to the reimposition of stalinism (during the so-called “normalization” period), and was expelled from the KSC.   After co-organizing and signing Charter 77, he was forced into exile.    In contrast to the courage and integrity of Mlynar, of Vaclav Havel and of their fellow members of the Czechoslovak opposition, the man who is currently Czech President, Vaclav Klaus, kept quiet during this period.

After departing Moscow in 1955, Mlynar and Gorbachev met again next in 1967.   When Gorbachev visited Prague in 1969, he was not permitted to see Mlynar.  They did not then meet again until 1989.    Mlynar was married to Rita Budinova (later Rita Klimova), the first post-Communist Ambassador from Czechoslovakia to the USA.

Archie Brown has noted that the reformers of communism in Czechoslovakia in 1968 were the same generation as those who reformed communism in the USSR twenty years later.  In both cases, the reformers were people who were born in the 1920s and 1930s, and who thus came of age after the imposition of communism.   Also, in both cases, the reformers were true believers in socialist ideas, and neither cynics nor opportunists. Unlike the situation in Hungary, Poland, and the DDR between 1945 and 1989, change to communism in the CSSR and the USSR came not from below but from above.

Past entries in this series are here.

Footnote:  Not only were the reforms of Gorbachev driven, leninist-fashion, from the top.  Charles Fairbanks [2008, pp. 64-65] has argued that there may be a direct link between the ideas of left-Stalinist Andrei Zhdanov (1896-1948), and Gorbachev’s reforms, via Finnish and Soviet politician Otto Kuusinen (1881-1964), Kuusinen’s protegé politician Yuri Andropov (1914-1984), and economists Aleksey Rumyantsev (1905-1993) and Aleksandr Yakovlev (1923-2005).  Rumyantsev was founding editor of the international journal Problems of Peace and Socialism in Prague from 1958-1964, and the journal’s Russian editorial staff in this period had been selected by Kuusinen and Andropov.  For example, Gorbachev’s close aide, Georgy Shakhnazarov (1924-2001), had twice worked for this journal in Prague, in between stints at the International Department of the Central Committee of the CPSU, working indirectly for Andropov, via Fedor Burlatsky (1927-2014).

References:

Charles H. Fairbanks [2008]: “The nature of the beast”.  Chapter 6, pages 61-75, of Gvosdev [2008].

Nikolas K. Gvosdev (Editor) [2008]:  The Strange Death of Soviet Communism:  A Postscript. New Brunswick, NJ, USA:  Transaction Publishers.

Mikhail Gorbachev and Zdenek Mlynar [2002]:  Conversations with Gorbachev on Perestroika, The Prague Spring, and the Crossroads of Socialism.  New York, USA:  Columbia University Press.  Translated by George Shriver, with a Foreword by Archie Brown.

Zdenek Mlynar [1980]:  Night Frost in Prague:  The End of Humane Socialism.  London, UK:  C. Hurst and Co.