Math 340, Set Theory and Logic
Day 3, 8/29/07
Managerial:
(1) (Quiz today)
(2) Homework is due Wednesday.
(3) Reading comprehension is due Monday.
(4) Memorization quiz is due one week from today. Answers on the website.
Activities, lecture, and in-class work.
(1) {(−1, x); x∈R}, from last time.
(2) Cardinality notation.
(3) Reminder: ∅ ⊆ {1,3,5}seems like a hard question.
(4) Logical tangles. True or false? (or “other”???)
(a) “all of my children like math”, (Hint: Actually I don’t have any children at all.)
(b) “The Math 340 professor either is male or has long hair.”
(c) You can get a discount at many movie theaters if you’re a student or senior citizen.
(d) “If George Bush is president1, then this is Math 340.
(e) “If you participate in class, you’ll get an automatic A.”, (Hint: There are no automatic A’s for anybody)
(f) “If pigs fly, you’ll get an automatic A.”
(g) “If pigs fly, then this is Math 340.”, (Hint: Trust me, it really is Math 340.)
(h) All real 30-foot-tall people are in this room.
(5) The reasons why we need to make these things clear, at least in our context.
1originally written 8/30/2007
