Math Problem Statement

(𝑝 ∧ π‘ž) β†’ π‘Ÿ (π‘Ÿ ∨ 𝑠) β†’ 𝑝 π‘Ÿ ∧ ~𝑝 ∴ 𝑠 ∨ π‘ž You should begin your answer by stating β€œValid” or β€œInvalid”, followed by your proof. You are not allowed to show your truth table (partial or full) in your answer, though you may use truth table in your own rough work to help you derive your proof.

Solution

Invalid.

Here's the proof for why this argument is invalid:

Premises:

  1. (p∧q)β†’r(p \land q) \to r (Premise 1)
  2. (r∨s)β†’p(r \lor s) \to p (Premise 2)
  3. r∧¬pr \land \neg p (Premise 3)

Conclusion to Prove:

s∨qs \lor q

Analysis:

Step 1: Analyzing Premise 3

From r∧¬pr \land \neg p, we know that:

  • rr is true.
  • pp is false.

Step 2: Implications from Premise 2

Consider (r∨s)β†’p(r \lor s) \to p. Since pp is false (from Step 1), the only way for (r∨s)β†’p(r \lor s) \to p to hold true is if r∨sr \lor s is false. Therefore:

  • r∨sr \lor s must be false.
  • Since rr is true (from Step 1), it follows that ss must be false to make r∨sr \lor s false.

Thus, ss is false.

Step 3: Implications from Premise 1

Now consider (p∧q)β†’r(p \land q) \to r. Since rr is true (from Step 1), this tells us nothing about p∧qp \land q, because the implication is satisfied when the consequent rr is true, regardless of whether p∧qp \land q is true or false.

Step 4: Final Conclusion

Given that ss is false (from Step 2), for s∨qs \lor q to be true, qq must be true. However, none of the premises give us any information about the truth value of qq. It could be either true or false.

Therefore, the argument does not guarantee the truth of s∨qs \lor q. Since the conclusion s∨qs \lor q cannot be definitively derived from the premises, the argument is invalid.


Would you like further details or clarifications? Here are some related questions:

  1. How would the truth table for this argument look?
  2. Can you prove the argument is valid using natural deduction?
  3. What happens if pp is true in Premise 3?
  4. Can we modify the premises to make the argument valid?
  5. How can we represent this argument symbolically in terms of a proof system?

Tip: Always verify the truth of each proposition step by step to see if the conclusion follows logically from the premises.

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Math Problem Analysis

Mathematical Concepts

Propositional Logic
Logical Implication
Logical Connectives

Formulas

Implication (p β†’ q)
Disjunction (p ∨ q)
Conjunction (p ∧ q)
Negation (~p)

Theorems

Modus Tollens
Contradiction

Suitable Grade Level

College Level - Logic Course