1. Show that the following argument with hypotheses on lines 1-2 and conclusion on line c is valid using the rules of inference and logical equivalences. Clearly label each step. 1 p → q Premise 2 (r ∨ s) → (p ∧ ¬q) Premise . . . c ¬r Conclusion
Question
- Show that the following argument with hypotheses on lines 1-2 and conclusion on line c is valid using the rules of inference and logical equivalences. Clearly label each step. 1 p → q Premise 2 (r ∨ s) → (p ∧ ¬q) Premise . . . c ¬r Conclusion
Solution
To show that the argument is valid, we need to derive the conclusion ¬r from the given premises using the rules of inference and logical equivalences.
- p → q (Premise)
- (r ∨ s) → (p ∧ ¬q) (Premise)
- ¬(r ∨ s) ∨ (p ∧ ¬q) (Material implication, 2)
- (¬r ∧ ¬s) ∨ (p ∧ ¬q) (De Morgan's law, 3)
- (¬r ∨ (p ∧ ¬q)) ∧ (¬s ∨ (p ∧ ¬q)) (Distribution, 4)
- (¬r ∨ (p ∧ ¬q)) (Simplification, 5)
- ¬r (Disjunctive syllogism, 6)
Therefore, we have derived the conclusion ¬r from the given premises, and the argument is valid.
Similar Questions
From the premises ¬¬P ∨ Q, P ↔ R, and H → ¬Q derive H → P using the inference rules and equivalence lawsfrom the lectures. Start with the premises and state in each step which rule you are using. Following from this, Let¬¬P ∨ Q be true and H → ¬Q be true. Prove that H → P is true by contradiction.
Which of the following is the study of the principles of valid Inference and demonstration?Question 2Answera.Factb.Logicc.Ruled.Argument
Select the correct answerThe premises (p ∧ q) ∨ r and r → s imply which of the conclusion?Optionsp ∨ sp ∨ rp ∨ qq ∨ r
State whether each of the following propositions is a tautology or a contradiction or contingent (i.e. neither).You must give a (brief) reason to justify each of your answers.(a) P(b) (P ∧ Q) → (P → Q)(c) ¬(P → Q) → (¬Q)(d) (¬Q ∧ (P → Q)) → ¬P(e) ((P → Q) ∧ (Q → R)) ↔ (P → R)(f) (R ∨ P ) → (P ∨ (Q ∨ R))
Assume that all of the following are true(P ∨ Q) ⇒ RQ ∨ RR ⇒ PShow by contradiction that P is true.3
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.