Notes to Future Self
Yesterday I was tidying up a bit and came across the old notebooks I used when I was a research student. As I suppose is the case with everyone else, there’s quite a lot in them that never went anywhere. If you can read the example above, about 3/4 of the way down the right-hand page I left a note saying “This is a pointless task”. I can’t remember if that referred to that particular integral or my research in general!
Some people who have seen this picture remarked on the size of my integral signs. That’s because I had to do quite a lot of integrals with complicated integrands, so I got into the habit of drawing big integral signs as a prelude to writing down what I assumed would be a horrible formula.
The way I worked in those days (1985-88) was to do a lot of rough scribblings on scrap paper. When I got to something I thought was promising I would write up a “neat” version in the notebook and throw away the workings. I know younger folks these days do most of their work on a screen but, as an old fogey, I still write a lot down on paper or on a blackboard. I didn’t have my own blackboard when I was a PhD student, but I did have plenty of notebooks – most of which I have kept. I think that I’ll always find an essential part of the mathematical thought process involves a pen or piece of chalk in my hand, moving around and guiding my brain.
Looking through these books I remember that I also wrote down ideas for follow-up projects. I managed to do very few of these, but some were done by other people elsewhere independently of me, so at least they were reasonable ideas!

July 28, 2023 at 1:35 pm
I believe that the infinitesemal element dx (or dz or whatever) should be written immediately after the relevant integral sign. This saves a lot of brackets and it is a mystery to me why many textbooks do not do this.
July 28, 2023 at 1:45 pm
I do that now in my solutions to exams, etc. I found though that doing a numerical integral as a set of nested sums with the integrand in the middle it helps to write the elements dxdydz in the correct order afterwards.
July 28, 2023 at 11:12 pm
Wonderful. Grad & Ris is I guess
“Tables of Integrals, Series, and Products” by I. S. Gradshteyn and I. M. Ryzhik.
It is a long time since I have looked at my copy, Mathematica being speedier nowadays.