Fall 2018

Here is a running schedule of the problems that are assigned for as our problem sets throughout the term. Remember that the problem set exercises are not the upper limit of the problems you should do: *The more exercises from the book you try, the better off you will be.*

Unless otherwise noted, problem sets are always due by the beginning of class on the due date. Each PS is worth 30 points. Each individual problem is worth 6 points unless otherwise indicated.

If an assignment has a written-out portion, you may either (a) bring it to class on the day it’s due, (b) slip it under Mark’s office door before it’s due, or (c) send it in an e-mail it to Mark before it is due. Whenever you submit a written portion of a problem set via email, please make sure to write “Written Portion: PS #” in the subject line, letting us know that your e-mail contains a written portion to be graded and telling us which problem set number it is for.

Hints and Solutions for some of these exercises are available under the “For Students” section of the LPL web site, where indicated below.

**Due:** on Friday, Oct. 26 by 5 p.m.

- 7.12
- 7.15

- 8.25
- 8.32

- 8.35

The problems from Chapter 8 involve proofs, so start working early!

**Due:** Wednesday, October 3

- 6.14
- 6.25 (don’t worry about doing the “informal proof”)
- 6.31
- 6.32
- 6.35

Make sure to read the instructions for each problem; some of them will ask you first to determine whether the argument is valid or invalid and *then* complete the exercise accordingly. *(It is never fun to spend several hours trying to construct a proof of an argument only to find out that it is invalid and no proof is available.)*

**Start early!** Proofs are hard, and you’re more likely to get stuck and need help with these problems than with the earlier problem sets.

My advice from the syllabus is especially apt when it comes to proofs: Treat the problem set as the bare minimum group of problems, and go on to do as many other exercises from the book as you can stand.

When you receive your official “Instructor Too” report for PS 3, the Grade Grinder will say some things that might worry you, but which are not really a problem:

- For exercises where you are not told in advance whether the argument is valid or invalid, it will tell you exactly what you did and did not submit. So, for instance, if you submit a proof for a valid argument, it will still tell you that you did not submit a world file. But that is not a problem: you
*shouldn’t*be submitting a world for valid arguments. (The same thing goes in reverse for invalid arguments: it will tell you that you didn’t submit a proof, but that’s okay.) - Also, Grade Grinder will tell you how many steps beyond the premises were in any proof you submitted. There is no need to worry about this, either.
For EXERCISE 6.25, GG will say

???? We did not receive your written work. We hope you turned it in to your instructor.

That is referring to the informal proof that you did not have to do. So, again, no need to worry.

**Due:** Monday, September 24, by 5 p.m.

- 4.6
- 4.8 (use Handout 6, please)
- 4.17
- 4.22
- 4.23

For Exercise 4.8, use worksheet from Handout 6, which has the Euler diagram already drawn on it.

**Due:** Friday, September 14 by 5 p.m.

- The “find-the-main-connective” worksheet
- 3.10
- 3.13
- 3.15
- 3.21

Note that this is a very late due date for this problem set; it is due in the third week of the semester. You can and *should* start working on this problem set earlier than this date would suggest.

**Note:** Problem 3.10 asks you to submit **both** files when you’re done. It’s asking for the world file that you modified and renamed as “World 3.10.wld”, and it also wants you to submit the sentence file. The Grade Grinder will complain if you do not submit the sentences, but I don’t care whether you do so or not, and you will not lose points for not submitting them. I am confident you can type.

If you get stuck on 3.21, you can find some help in the “Hints” file for Chapter 3 from the LPL web site. Also, note that Exercise 3.22, *which is not assigned*, can help you check your answers to Exercise 3.21.