I have been putting some serious time into research this week, and in order to avoid the curse of knowledge, I have to come up with some clever examples. One of the examples I was working was that of a passenger waiting for an elevator. The passenger has the information of which floor the elevator is on by the floor-indicator (what really is the name for that thing?). As I was sketching the solution, I started to sketch a drawing to go along with it. Sometimes a picture is word at least fifty words.
This is where I collect all of my blunders, flaws, fallacies, miscalculations, inaccuracies, and other miscellaneous grammatical and mathematical howlers in Basic Discrete Mathematics. The name of the person who found the erratum is listed at the end. RK is me.