Question 10

[cyarelson]

This reads:

N will be selected only if J is selected.

And the answers are:

-J -> -N or J -> N

How is -J -> -N the correct answer when the statement is positive?

[tommywallach]

Hey Cyar,

Well, if we know that N will be selected ONLY if J is selected, that means that if there's no J, there will be no N. So the way we notate that is:

-J --> -N

Remember, every statement has a contrapositive, so there's no such thing as a "pure" positive or negative statement. It's more a question of WHERE the negatives will end up going.

-t