| Introductory Logic |
Quiz #5
|
October
14, 2005
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| Name: ________________________ |
R. Hammack
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Score: _________
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| (a) | ( S • R ) ⊃ ( ~S ≡ R ) | |
|
(
|
S
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•
|
R
|
)
|
⊃
|
(
|
~
|
S
|
≡
|
R
|
)
|
|
T
|
T
|
T
|
F
|
|
F
|
T
|
F
|
T
|
|||
|
T
|
F
|
F
|
T
|
F
|
T
|
T
|
F
|
||||
|
F
|
F
|
T
|
T
|
T
|
F
|
T
|
T
|
||||
|
F
|
F
|
F
|
T
|
T
|
F
|
F
|
F
|
| (b) | ~( R • S ) | |
|
~
|
(
|
R
|
•
|
S
|
)
|
|
F
|
T
|
T
|
T
|
||
|
T
|
F
|
F
|
T
|
||
|
T
|
T
|
F
|
F
|
||
|
T
|
F
|
F
|
F
|
| 2. | Is statement (a) from Question 1 contingent, tautologous or self-contradictory? | |
CONTINGENT
| 3. | Are statements (a) and (b) from Question 1 logically equivalent, contradictory, consistent or inconsistent? List all that apply. | |
LOGICALLY EQUIVALENT and CONSISTENT
4. Decide if the following argument is valid or invalid by writing out its truth table.
| ~(G • M) |
| M ∨ ~G |
|
|
| ~G |
|
~
|
(
|
G
|
•
|
M
|
)
|
/
|
M
|
∨
|
~G
|
//
|
~
|
G
|
|
F
|
T
|
T
|
T
|
|
T
|
T
|
FT
|
|
F
|
T
|
||
|
T
|
T
|
F
|
F
|
F
|
F
|
FT
|
F
|
T
|
||||
|
T
|
F
|
F
|
T
|
T
|
T
|
TF
|
T
|
F
|
||||
|
T
|
F
|
F
|
F
|
F
|
T
|
TF
|
T
|
F
|
VALID, because in every line where the premises are both true (the 3rd and 4th) the conclusion is true also.