I spent some time thinking about why a partition of an interval is finite. I didn’t come up with a definite conclusion. I can understand that finite sums are easier to deal with than countably infinite sums, but I couldn’t exhibit any problems with a countably infinite “partition” except by making the function unbounded.

I finished the final problem in section 11.2 and worked through section 11.3 (did not finish working through the exercises).

I started a page called Understanding definitions.

I submitted some corrections for Tao’s book Analysis I (they were added to the page on 2018-12-05).