# Introduction to Logic Exam 2

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1. When does p → q come out false?
• Only when p is true and q is false
• (When p is false, it comes out true regardless of what q is)
2. When does pVq come out false?
• Only when both p and q are false
• (When p is true, it comes out true regardless of what q is)
3. How do you find validity in a truth table?
• It's valid if it's always true
• It's invalid if at least one thing comes out false
4. How do you do the invalidity shortcut method?
• 1. Start with the conclusion if there's only one way to make the conclusion false
• OR
• Start with the premises if there's more than one way to make the conclusion false
• 2. Make the conjunction turn into T→F form
5. What does Modus Ponens (MP) look like?
• p→q
• p
• //q
6. What does Modus Tollens (MT) look like?
• p→q
• -q
• //-p
7. What does Absorption (Abs) look like?
• p→q
• //p→(p⋅q)
8. What does Disjunction Syllogism (DS) look like?
• pVq
• -p
• //q
9. What does Hypothetical Syllogism (HS) look like?
• p→q
• q→r
• //p→r
10. What does Simplification (Simp) look like?
• p⋅q
• //p or //q
11. What does Conjunction (Conj) look like?
• p
• q
• //p⋅q
12. What does Addition (Add) look like?
• p
• //pVq
13. What does Constructive Dilemma (CD) look like?
• (p→q)⋅(r→s)
• pVr
• //qVs
14. What does Commutation (Comm) look like?
• (pVq)↔(qVp)
• OR
• (p⋅q)↔(q⋅p)
15. What does Association (Assoc) look like?
• (pV(qVr))↔((pVq)Vr)
• OR
• (p⋅(q⋅r)↔((p⋅q)⋅r)
16. What does De Morgan's Law (DeM) look like?
• -(pVq)↔(-p⋅-q)
• OR
• -(p⋅q)↔(-pV-q)
17. What does Implication (Imp) look like?
(p→q)↔(-pVq)
18. What does Transposition (Trans) look like?
(p→q)↔(-q→-p)
19. What does Equivalence (Equiv) look like?
• (p↔q)↔((p→q)⋅(q→p))
• OR
• (p↔q)↔((p⋅q)V(-p⋅-q))
20. What does Exportation (Exp) look like?
((p⋅q)→r)↔(p→(q→r))
21. What does Tautology (Taut) look like?
• p↔(pVp)
• OR
• p↔(p⋅p)
22. What does Double Negation (DN) look like?
p↔--p
23. What does Distribution (Dist) look like?
• (pV(q⋅r))↔((pVq)⋅(pVr))
• (p⋅(qVr))↔((p⋅q)V(p⋅r))
 Author: mirahh ID: 263536 Card Set: Introduction to Logic Exam 2 Updated: 2014-03-09 18:43:09 Tags: suny geneseo intro logic phil 111 Folders: Description: Covers stuff for the second exam Show Answers: