**For Monday’s class, here’s your checklist:**

**If you are just joining the class,**please look at the handouts on the Resources page for an update on what we’ve done, and also read the previous daily posts (left navigation bar) and go through the daily checklists there. The first day we did a general warmup activity about polyhedra. On the second day we did a first proof (see the associated handout).- Both days we worked in (the same) groups and shared contact info.
**Make sure you are part of a study group and have arranged one hour to meet your group outside class before Friday.**The groupwork assignment can be found on the Resources page. If you are having insurmountable troubles meeting, consider skyping in. If that really won’t work, or if you don’t have a group, please email me (kstange@math.colorado.edu).**Group homework is due Friday at 8 am.** - Reminder: please contact me ASAP if you have an ADA accommodation, or if you’d like to discuss how I address you, concerns about religious accommodations, etc.
- Please read Chapter 1 of Hammack, up to the end of Section 1.1 (i.e. pages 3-7). This introduces the notion of a set. Please read actively. One thing this means is that whenever you come across an assertion, you try to create your own novel examples and non-examples. Every example you should work through yourself (e.g. for Example 1.1, cover the right side of the equation and guess what is there, then compare). Three pages of active reading can take a long time!
- Make a summary sheet giving the “cliff notes” version of the reading. This doesn’t need to be detailed; an outline of the big points is the goal.
- Do as many exercises for Section 1.1 as you feel is appropriate. If you are finding the reading difficult, then focus on reading for now, or just one topic for now. If you felt you understand the reading, then do all the odd numbered problems (answers in the back), to make sure. Some of them may trip you up!
- Note: this assignment, done right, is a challenge to everyone, but for everyone it is a challenge in different ways. There’s always more to understand. (If you really feel everything is easy, and you got all the exercises in an instant, then challenge yourself by inventing interesting questions, corner cases, and trickier problems, or read section 1.10, or ponder how sets could be used to define the integers, or define the real numbers.) Put in an hour of solid effort and get where you get.
- Late addition! You may enjoy this video of our first proof, and this very short video about sets.