Monday, November 10, 2014

Sleeping beauty problem IV

Previous post in this series

I have been waiting to see some conclusions coming from discussions of the problem at the Stubborn Mule blog, however the discussion seems to have petered out without a final statement. I admit I did not read the details of Giulio Katis's mathematical model, even though it was very closely related to the (sequential part of ) the compositional model of Markov chains that de Francesco Albasini, Sabadini and I developed in "The Compositional Construction of Markov Processes, Applied Categorical Structures 2011",  "The Compositional Construction of Markov Processes II, RAIRO - Theor. Inf. and Applic., 2011", and in Luisa's PhD thesis at the University of Insubria, Como, 2011.

However I remain convinced that the matter is simple and I would like to make a couple of mathematical comments.

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Monday, November 03, 2014

Stephen H. Schanuel and Dietmar Schumacher

Steve and Dietmar are two mathematicians I knew who died earlier this year. I meant to write something earlier but have been distracted by my own health problems.

I knew Stephen Schanuel (14 July 1933-25 July 2014) mainly from his visits to Sydney. During his 1988 visit my friend Bob Bolton took this photograph of him:
My memory of him is that he was enthusiastic as a mathematician, but also Missouri-Skeptical of exaggerated claims. I remember he was not very keen on the word "categorification" though of course being well aware of the process of abstraction from objective categories. To visit Buffalo was to be involved in the ongoing Lawvere-Schanuel mathematical discussions. I liked very much Fred Linton's remarks on Steve's death on the Categories List in which he said "no longer does Steve belong so exclusively to his peers, colleagues, friends, and family, as to History".

I also knew Dietmar (who died on 17th September 2014) from visits to Sydney (I think actually to Macquarie University), and from a visit I made to Wolfville, Nova Scotia.  He was great company, and had the odd habit of apologizing, even to the extent of apologizing for apologizing. He was the founder with Bob Paré of the Atlantic Category Seminar and wrote extensively with Bob Paré on indexed categories