Reminiscences of John Derrick
We first met at an interview for a position in the Mathematics Department at
Leeds University in early summer 1962 (June or July); we were put up in the hotel
on King Street (still there, can't remember the name, Majestic?)
Harold Ruse came to see us on the evening before the interviews.
He and Prof Craggs and I think the Registrar and someone else interviewed us next day, and appointed at least three of us (I think Nick Romilly was appointed then; there were eight appointed new to the Math Dept that summer, Terry Talintyre and Bob Hart were included but I can't remember all the others, and I may be misrembering!)
John and I travelled back on the same train to Peterborough, I went back to Cambridge, John to London.
I took up the post in September 1962, John didn't start until January 1963 because he had to give notice to the School where he was teaching.
We met again in August 1962 at the meeting of the British Logic Colloquium (BLC) organised by Martin Löb and Harvey Rose, at Devonshire Hall. It was the second European meeting of the ASL (first was in Amsterdam, 1958). Alonzo Church, Kleene, Tarski were there (amongst others). John came along with Margaret and Cathy; John Jr. was not yet.
John had been working on a part time PhD with Geoffrey Kneebone, working on Cantor's diagonal method in set theory. He told us a bit about it in a seminar, my impression was that he wasn't very impressed himself with it, he never wrote a thesis or published anything from it.
I got to the meeting in Berkeley in the summer of 1963, where Paul Cohen announced the independence of the Axiom of Choice and the GCH. Later that summer, at a meeting of the BLC in Bristol, John got a copy of Cohen's paper from John Shepherdson and we studied that and looked for further results using the forcing method. We did produce results, and eventually a paper presented at the BLC Leicester 1965 and published in the proceedings in 1967: "Independence of the Axiom of Choice from Variants of the GCH".
The introduction to that paper says that "the authors plan a further paper which will discuss ... syntactic questions, and also a further strengthening of the model theoretic results". The syntactic questions never really got into print anywhere; the model theoretic strengthenings were drafted (by me; I don't think John ever approved my drafts) and presented at later BLC meetings, there are two abstracts in the JSL.
Although we did a great many more things together, we didn't produce any further mathematics together.