More school stuff

- I have just finished creating, assigning, collecting, and grading the first homework assignment of the year as a TA. This homeowrk was about formal logic, including propositional and first-order logic. (Propositional logic just has variables which can be either true or false, while first-order logic allows variables to be arbitrary objects, there are "predicates" that are basically functions which take objects as arguments and return a boolean variable, and there are "quantifiers" which allow you to say things like "for any X, P(X) is true" or "there exists an X such that Q(X) is true". We thought this part would just be review (these are Masters students in computer science, so we thought they would already know about logic) but some of them had trouble with simple things like the difference between validity (statement is true all the time regardless of the values of the variables) and satisfiability (statement is true for some assignment of values to the variables.) In fact one of the problems we had to "cancel" and make it an extra credit problem because it had to do with proofs in first-order logic, a topic we didn't cover (I didn't realize that we weren't going to cover it when I wrote the homework, and the professor didn't notice when he was looking at the homework before posting it)

- I have my Ph.D. qualifying examination this Thursday and Friday. I have looked at most of the previous quals and it seems like I pretty well prepared for it. Another thing is even if I do decide to only get a Masters degree, passing the qual is a good idea because if I pass the qual I am exempt from the distributional requirements for a Masters (there are still two distributional requirements, hardware and systems, that I haven't taken courses in so I would need to do that if I were to go that route).