Overview
With both the preliminaries and the workflow established last week, this week we begin our study of logic and proofs.
Friday, Feburary 14th
Classwork
Dear Students, I'm our sick today, so please do what you need to do to move forward without me. Read through the next section, and work all the exercises. We meet again next Wednesday, when we will review both 1.1. and 1.2, and prepare for our first quiz on Friday. Blu asked me yesterday for a list of questions to pay particular attention to. I promise to have that finished over the weekend.
Here are the two steps needed to get truth-table-generator working on your school Macbook:
- Run:
python3 -m pip install truth-table-generator
- In your
.zshrc
file add this line to the bottom:export PATH=$PATH:$HOME/Library/Python/3.11/bin
We'll begin class by discussing the exercises from Section 1.1: Mathematical Statements. I'll share my notes from this section, and use them for a brief discussion of how to take notes on this material.
I'll randomly choose students to share their solutions to a few of the exercises.
We will then discuss Section 1.2: Implications.
Challenge
Run:
ttg_cli.py "['P', 'Q']" -p "['P => Q', 'Q => P', '~Q => ~P', '~P => ~Q']" -i False
in your terminal. What do you observe?
Homework
Complete the Reading Questions, Practice Problems, and three Additional Exercises at the end of the section. Come to our next class prepared to discuss these exercises.
Monday, February 10th
Classwork
Today in class we will discuss Section 1.1: Mathematical Statements in our text. Since it will be so useful to us as we explore logical statements, we will start by installing truth-table-generator and learning how to use it to investigate the mathematical statements presented in the section.
Unfortunately, I do not have access to a student impaired Macbook on which to
test how you will have to work around your restrictions. During first period
Toby put together a
shell script to
install the application. During fourth period I hope we can refine this a
bit, using it to as a teachable moment
to better understand the
challenges of installing software.
That done, we will work through the following examples together.
ttg_cli.py "['p']"
ttg_cli.py "['p', 'q']"
ttg_cli.py "['p', 'q', 'r']"
ttg_cli.py "['p']" -i False
ttg_cli.py "['p', 'q']" -p "['~(p and q)', 'p or ~q']" -i False
ttg_cli.py "['p', 'q', 'r', 's'] -i False"
-
ttg_cli.py "['p', 'q']" -p "['p and q', 'p or q', 'p => q']" -i False
Challenge I
Find a statement logically equivalent (i.e. having the same truth table)
to p => q
using or
and ~
operators.
Challenge II
Given the following propositional variables:
- p: Troll 1 is a knave.
- q: There are exactly two knights.
- r: Troll 1 is lying.
- s: All 3 Trolls are knaves.
use truth-table-generator
to explore the Investigate!
activity in the Section Preview of Section 1.1 Mathematical
Statements. See if you can determine which Trolls are knaves and which are
knights.
Homework
Take notes on section 1.1, and learn the following vocabularly and be prepared to use it correctly:
- premise
- conclusion
- argument
- theorem
- proposition
- proof
- statement
- quantifier
- predicate
- logical connective
- binary connective
- unary connective
- truth value
- propositional variables
- conjunction
- disjunction
- implication
- conditional
- biconditional
- negation
- truth conditions
Complete the Reading Questions, Practice Problems, and three Additional Exercises at the end of the section. Come to our next class prepared to discuss these exercises.