## 3.4 Outline

- Introduction
- theorem
- syllogism

- Direct reasoning
- definition
- modus ponens
- law of detachment
- assuming the antecedent

- Indirect reasoning
- definition
- modus tollens
- denying the consequent

- Transitive reasoning
- definition
- formulate a conclusion

- Logical proof
- Fallacies
- fallacy of the converse
- also called fallacy of assuming the consequent
- counterexample

- fallacy of the inverse
- also called fallacy of assuming the consequent
- counterexample

- fallacy of the inverse
- fallacy of the antecedent
- test validity

- false chain pattern

- fallacy of the converse

## 3.4 Essential Ideas

There are three types of syllogisms considered in the text:

These forms can be mixed together in a single problem.

In addition there are three common logical fallacies considered:

Remember this forms are NOT valid: