S. told me to prove the lemma "A iff B" (from his soon-to-be published book) for practice. "A only if B" was really easy, but the other direction was not clear. I tried it many different ways, and reduced it to several different statements C, D, E. I did not know whether C, D, or E was true. So I asked S. in our meeting today "is it the case that C?" and he said, "of course not!" This was befuddling, and I lost my way for awhile, so we talked about it. After both staring at it for a long time, I figured out that "A if B" was false by coming up with a counterexample.
Book debugging: a story of triumph!
This post's theme word: keming, "the result of improper kerning."