Chapter Three, Tutorial Five
In this chapter we will consider two concepts that involve sets of sentences.
Validity in SL
First consider the following argument:
Bob will attend law school if he does well on the LSAT's.
Back in chapter one, we called such an argument "valid". Roughly the idea of validity was that the truth of the conclusion is inescapable given the premises.
But as usual, we gave the official definitions in terms of possibility. Let's try to recall, an argument is valid if and only if ______. If and only if what??? Select the correct way to fill in the blank: