Identify the form of the following argument and to determine whether the argument is valid or invalid.
If Tanner won't be at work tomorrow, then he must try to find a substitute. He won't be at work tomorrow. Therefore, he must try to find a substitute.
Valid
p→ q
q→r
pr
• Valid
p-q
~p
~q
Invalid
p-q
~p
~q
O Valid
p-q
q
Invalid
pq
q
This is a valid argument. It is in a valid form of modus ponens:
p → q
p
∴ q
In this case:
p = Tanner won't be at work tomorrow
q = He must try to find a substitute
Therefore, the argument is valid.