EXAMPLE 2.2.14
SOLUTION
Let p: ÒI hire
Gomer.Ó
Let q: ÒI hire
Gomer.Ó
Let r: ÒIÕm not having a bad hair day.Ó
The argument has
this form:
Now we make a
truth table.
|
p |
q |
r |
~q |
pòq |
~q¨r |
~p |
~r |
|
T |
T |
T |
F |
T |
T |
F |
F |
|
T |
T |
F |
F |
T |
T |
F |
T |
|
T |
F |
T |
T |
T |
T |
F |
F |
|
T |
F |
F |
T |
T |
F |
F |
T |
|
F |
T |
T |
F |
T |
T |
T |
F |
|
F |
T |
F |
F |
T |
T |
T |
T |
|
F |
F |
T |
T |
F |
T |
T |
F |
|
F |
F |
F |
T |
F |
F |
T |
T |
The fifth row of
the truth table shows that the argument is invalid.