Propositional Calculus
Decide which of the following conclusions are valid and which are invalid. The answers are at the end of the chapter
1. Affirming the antecedent.
If today is Tuesday, then I have my bowling class.
Today is Tuesday.
Therefore, I have my bowling class.
2. Affirming the consequent.
If Sarita is a psychology major, then she is a student.
Sarita is a student.
Therefore, Sarita is a psychology major.
3. Denying the antecedent.
If I am a first-year student, then I must register for next semester’s classes today.
I am not a first-year student.
Therefore, I must not register for next semester’s classes today
4. Denying the consequent.
If the judge is fair, then Susan is the winner.
Susan is not the winner.
Therefore, the judge is not fair.
