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    • CommentRowNumber1.
    • CommentAuthorjesuslop
    • CommentTimeDec 23rd 2019

    Changed “interval functor” to “cylinder functor” in “While this is the motivating example, the interval functor need not be of that form”, in Remarks.

    diff, v10, current

    • CommentRowNumber2.
    • CommentAuthorDavidRoberts
    • CommentTimeJan 19th 2021

    Clean up reference to Richard W’s thesis (he’s not in math genealogy, so I don’t know the actual year of it, only the arXiv submission year)

    diff, v11, current

    • CommentRowNumber3.
    • CommentAuthorTim_Porter
    • CommentTimeJan 20th 2021
    • (edited Jan 20th 2021)

    Added the date. (although Richard might want the date that it was ‘awarded’ i.e. the ceremonial date, rather than the date it was approved for the award!)

    diff, v13, current

    • CommentRowNumber4.
    • CommentAuthorDavidRoberts
    • CommentTimeJan 20th 2021

    Fixed a typo in the arXiv link text for Richard’s thesis, and changed the date of reference from 2013 to 2012

    diff, v16, current

    • CommentRowNumber5.
    • CommentAuthorRichard Williamson
    • CommentTimeJan 22nd 2021
    • (edited Jan 22nd 2021)

    Thank you both! I actually do not fully remember when the ceremony was, but I think it was the spring or summer of 2013! Yes, approved 2012 and submitted the autumn of 2011! The Bodleian library reference is here.

    Funny to think back that I wrote the entire thesis in a burst of effort in a month, after moving to Norway from Oxford in August 2011! I had by chance discovered Tim’s book in the tiny mathematics library of the old Oxford mathematics institute (I have not been to the new one, but I imagine the library is bigger), which if I recall correctly was on the top floor (edit: or maybe not, maybe the first floor; I remember that one had to climb the stairs in any case!), not long before leaving for Norway, and that was the main inspiration for the thesis, though some hard work was needed to get the full model structures; I can’t really remember how I came up with some of the ideas, but I do remember going for some evening walks during that month fervently manipulating commutive diagrams in my head to try to get things to work, so it was not as though everything was fully worked out! I had a broad vision of which the thesis was just to be the first step (as I say, although coming up with model structures for higher categories was something I had been thinking about for a long time, this actual thesis topic was more or less spontaneous!), but things didn’t turn out that way; I am still fond of the ideas and that vision, though.

    Thus even if it were the case that nobody else had ever read your book, Tim, it played an important part in my life!!

    • CommentRowNumber6.
    • CommentAuthorRichard Williamson
    • CommentTimeJan 22nd 2021
    • (edited Jan 22nd 2021)

    Other interesting (stressful would be a better word at the time!) aspects of that month were discovering a couple of mistakes in the literature. One was in Peter May’s books; he initially vigorously defended the correctness of it, but I was sure I was correct, and double-checked with my friend Tobias Barthel, who is very sharp, and eventually May did acknowledge it. Tobias became interested in finding a way around the mistake, eventually leading to his first couple of papers, with Emily Riehl; his work has long since completely eclipsed anything I have ever done, but I feel happy to have played a small part in kick-starting that!

    Another was a technical mistake in some work of Marco Grandis; he acknowledged the mistake, but basically just said he was working on something else at the time and didn’t have time to try to correct it; I am not sure he has ever acknowledged the mistake publically, and I remember that I was not especially impressed at the time with his response! It is pointed out in my thesis, I think; like the one in May’s work, it is not the kind of thing that is easily corrected, and since time was very short, I basically just discarded these things as barren paths, and found a different way to proceed!