Final answer:
To prove that r is a valid conclusion, we can use the deduction rule called modus tollens. Modus tollens states that if the conditional statement ¬r → p is true, and p is false, then ¬r must be true. By applying this rule to the premises given, we can conclude that r is a valid conclusion.
Step-by-step explanation:
Premises:
- (p → ¬q) ∧ q
- ¬r → p
Argument:
To prove that r is a valid conclusion, we can use the deduction rule called modus tollens. Modus tollens states that if the conditional statement ¬r → p is true, and p is false, then ¬r must be true. In our premises, we have (p → ¬q) ∧ q, so using modus tollens on this premise, we can conclude that if p is false, ¬q must be true. Combining this with the second premise ¬r → p, we can apply modus tollens again to conclude that if ¬r is true, p must be false. Therefore, we have shown that if ¬r is true, then p is false, which means r must be true.