Today we are going to start the topic Logic, our 9th unit.

Logic deals with the conversion of worded statements into symbols and is the study of correct reasoning.

Logic involves many concepts which you have to learn. We are going to tick them off, one by one:

- Proposition
- Negation
- Truth tables
- Conjunction
- Disjunction
- Exclusive disjunction
- Logical Equivalence
- Tautology
- Logical contradiction
- Implication
- Equivalence
- Converse
- Inverse
- Contrapositive
- Valid arguments

Today: Propositions, negation, conjunction and disjunction. And, an introduction of truth tables.

#### Propositions

– Statements that are either *true* or *false*.

– Use the notation p: or q: (or other letters, such as r and s)

#### Negation

– The negation of a proposition is ”not p”.

#### Conjunction

Join two propositions with the word *and*.

#### Disjunction

Join two propositions with the word *or*.

page 233, 8A.1 1-3, page 236, 8B.1, 1-3.