Lecture 9

Equivalence relations:

• Equivalence relation proof from 6.6
• Another example of equivalence classes: sets of integers with the same cardinality.

chapter 7 (functions and onto).

• Basic function definitions
• What is "onto"?
• Understanding nested quantifiers
• The two onto proofs from section 7.9 and 7.11.

Announcements

• Midterm is Tueday, October 2nd, in class.
• Midterm review materials will appear very soon.
• The first honors homework is now available on our web site, due October 12th.