Videos for this class

Week 1:

Week 2:
• Definitions for sets (Today's handout (Jan 14) plus I added answers to the three homework questions that were due today).
Sample tests.

Test 1 with answers to questions 1 through 4 (for number of points for each question, click here). For next class, study these answers, and turn in question 5 if you haven't already.

Your HW for Thursday Feb 20 is: Read/watch/study the following handouts, then give two proofs for the first part of exercise 5 in section 2.2 (see the last handout for hints):

HW for Tuesday Feb 25

Sample for test 2 (Do Ex 2, 3, 5. Turn in Ex 3) and more sample questions for test 2 (turn in Ex 6, 7, 8). Also do (not yet turn in): 2.4 Ex 1 and 2.

Some of the theorems in the book have very hard proofs, as you may have noticed in class today. Our next focus will be on how to use the theorems. Here it no longer matters that the proof was hard, as long as a proof exists, we are allowed to use these theorems. To make these theorems easier to use, they will be included in the test in the "list of facts".

Many of the exercises are designed to test if you can use these theorems. For many exercises, the proof either

• (a) uses the right theorems (the right items in the list of facts),
• (b) or is ridiculously hard,
• (c) or is wrong.
About (a): That means, for each step you make, indicate which theorem justifies that step. To help you write short answers, you will have access to the list of facts during the test. That way you can justify a step with a short comment like "by item ...". If the item you cited justifies the step you made, then you are writing good proofs!

In test 1 the goal was to learn how to compute with statements. In test 2 the goal is to learn how to use statements. That's why it is so important to cite the right item in each non-trivial step. Please do that in your HW and in the test.

You can write diagrams in your scratch paper, but don't include them in your HW. Instead of diagrams or other intuitive explanations, you should justify each step in your answer by citing which item (from the list of facts) justifies that step.

Answers for: Sample for test 2 and more sample questions for test 2.

More sample questions: test 2 Fall 2019 and answers.

Test 2 (March 10, 2020) answers.