We will get back our Section 3.1: Propositional Logic tests today. The results for the class were good: A - 12; B - 2; C - 1; D - 6. The most prevalent misconception revealed by the test was how negation works with an implication. It was obvious from the tests that intiution about this is often wrong, providing us with one of the strongest arguments for studying formal logic and truth tables.

As usual, our friend José Ejemplo worked overtime to provide us with a nice solution guide to the test. We'll take a look at that at the beginning of class, and then resume our work on Section 3.2: Proofs.

We will begin class today by looking closely at the proof in our book of Theorem 3.2.1: There are infinitely many prime numbers. This is a wonderful example of a proof by contradiction, referred to in classical logic as reductio ad absurdum.

I'll check in with you to confirm you have listed this and the other proof techniques presented in our text.

Then we will use both the remainder of class and our homework time to begin working through the exercises at the end of the section.

Complete the Section 3.1: Propositional Logic test.

Read Section 3.2: Proofs taking notes in your git repo.