Lecture 4

We discussed some issues from the quiz, most notably:

• Whether zero is even or odd.
• Drawing conclusions from implications when you need to convert to the contrapositive.
• Why is there at least one fun-loving well-dressed animal?

We also did exercises on

• Incorrect conclusions from implications (Monty Python witch example)
• Building counter-examples
• Finding bugs in direct proofs, both in the math skeleton and in the style.

Announcements

• Our ACM chapter is holding an open house today at 7:00 PM in 1404 Siebel. The ACM and the WCS run the undergraduate social life of the computer science department. Well worth going.
• The PURE program (research for undergrads) is holding an informational meeting this Friday 5-6pm in Siebel 2405. Open to CS and ECE majors.

  Sir Galahad

• Discussions start today/tomorrow
• Office hours are posted.
• You still have a few hours to do the math prerequisites quiz.
• HW 2 should be posted later today.
• Everyone who contacted us earlier about trying to get into the class should have received email about an override. Be sure to register NOW because Monday is the last day to register for a class on-line.
• If you have just recently started trying to get into the class: keep an eye on the registration system. We're slightly over capacity but a few people might still drop by Monday.