Homework #2

Due: 9/12/02 (Thursday)

Section 1.2 Exercises 12, 16, 20, 32, 34, 39, 46

In Exercises 12-20, use propositional logic to prove that the argument is valid.

12.

16.

20.

For Exercises 30-37, use propositional logic to prove the arguments valid; you may use any of the rules in Table 1.14 or any previously proved exercise.

32.

34.

Using propositional logic, including the rules in Table 1.14, prove that each argument in Exercises 38-44 is valid. Use the statement letters shown.

39. If Jane is more popular, then she will be elected. If jane is more popular, then Craig will resign. Therefore, if Jane is more popular, she will be elected and Craig will resign.

J, E, C

46. The argument of the defense attorney at the beginning of this chapter was:

If my client is guilty, then the knife was in the drawer. Either the knife was not in the drawer or Jason Pritchard saw the knife. If the knife was not there on October 10, it follows that Jason Pritchard didn't see the knife. Furthermore, if the knife was there on October 10, then the knife was in the drawer and also the hammer was in the barn. But we all know that the hammer was not in the barn. Therefore, ladies and gentlemen of the jury, my client is innocent.

Use propositional logic to prove that this is a valid argument.