| Introductory Logic |
Test #2
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January 13, 2006
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| Name:_________________________ |
R. Hammack
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Score: _________
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| (a) | A day is a test day for Logic if and only if the day is a Friday and the month is January. | |
| (b) | I will give you a make-up test only if you request it. | |
| (c) | If Internet use continues to grow, then more people will become cyberaddicts, and normal human relations will deteriorate. | |
| (d) | We will have a picnic unless it rains. | |
| (e) |
If you hold down the shift key and press the delete button, then your computer will explode, and you'll have to buy a new one and rewrite all your files. |
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2. (20 points) Write out the truth tables for the following propositions.
For each proposition, say if it is tautologous, self-contradictory, or contingent.
| (a) | S ⊃ [(R • S) ∨ ~ R ] | |
| (b) | ~ [ ~ ( K ⊃ H ) ∨ ( H ≡ K ) ] | |
3. (20 points) Determine if the following pairs of statements are logically
equivalent, contradictory, consistent, or inconsistent.
| (a) | ~ ( X ⊃ Y ) | Y ∨ ~ X |
| (b) | A ∨ ( B • C ) | ( A ∨ B ) • ( A ∨ C ) |
4. (20 points) Use indirect truth tables to decide if the following sets
of statements are consistent or inconsistent.
| (a) | K ≡ ( A • ~P ) | A ⊃ ( P • ~S ) | S ⊃ ~ K | A • ~K | |
| (b) | ( Q ∨ K ) ⊃ C | ( C • P ) ⊃ ( N ∨ L ) | C ⊃ ( P • ~L ) | Q • ~N | |
5. (20 points) Use any technique from Chapter 6 to decide if the following
arguments are valid or invalid.
| (a) | Elvis was a space alien or he was not a hound dog. If Elvis was a space alien, then he's still alive. Thus, if Elvis was a hound dog, then he's still alive. |
| (b) |
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