Lecture 7

We covered selected hard topics from Chapter 5 (set theory). Specifically, we went over some notational and conceptual issues that often cause problems:

• Examples of set-builder notation.
• Two methods for figuring out complex notation: figuring out types, inserting a few concrete values.
• Vacuous truth and the formal definition of subset inclusion.
• Some gotchas with set notation.

And then we did the proofs of subset inclusion from sections 5.10 and 5.11.

Announcements

• Honors HW 1 should be out very soon. Probably due Oct 11th.
• Reflections/Projections is looking for volunteers. Great way to get involved and meet upperclassmen. See their slide.
• Midterm 1 is coming up in two weeks. Check the date (for Thursday's reading quiz!). Tell me NOW if you need special arrangements and book any necessary DRES rooms.
• At the end of Wednesday, we should be past the last of the extended extensions for folks who joined the class real late. So expect the HW 1 and HW 2 solutions to both appear around Thursday.