Oh yes that's a good write-up! At the very end > I follow the Kurzweil-Henstock approach to integration. ... I learned about this from advertisements by Rober

Oh yes that's a good write-up! At the very end > I follow the Kurzweil-Henstock approach to integration. ... I learned about this from advertisements by Robert G. Bartle in the Bulletin and the Monthly. I had just read https://math.vanderbilt.edu/schectex/ccc/gauge/letter/ https://math.vanderbilt.edu/schectex/ccc/gauge/letter/ so I got that reference :)