Chapter 9

Question 1

Truth-functional Logic

Answer 1

Propositional/sentential logic

Question 2

Claim Variables

Answer 2

Ps + Qs

Question 3

Truth Table

Answer 3

Any given claim P either T/F

Question 4

Negation

Answer 4

Contradiction to truth values of P (~P)

Question 5

Conjuction

Answer 5

Compound claim made from two simpler claims; conjunction true if both simpler claims true

Question 6

Disjunction

Answer 6

False only if both claims false

Question 7

Conditional

Answer 7

False if antecedent true and consequent false; Antecedent-first claim (P), Consequent-second claim (F)

Question 8

Truth-functionally Equivalent

Answer 8

Truth tables exactly same

Question 9

Modus Ponens

Answer 9

Conditional claim as one premise, claim affirms antecedent of conditional as second premise, claim affirms consequent in conclusion; P-Q. P, therefore Q

Question 10

Modus Tollens

Answer 10

Conditional one premise, negation of consequent other premise, negation of antecedent in conclusion; P-Q. ~Q, therefore ~P

Question 11

Constructive Dilemma

Answer 11

P-Q. R-S. P v R, therefore Q v S

Question 12

Destructive Dilemma

Answer 12

P-Q. R-S. ~Q v ~S, therefore ~P or ~R

Question 13

Conditional Proof

Answer 13

Assume P true and prove Q also true