In Rosen, page:17,example:2, there is a similar question.
q:"you can ride roller coaster"
r:"you are under 4feet tall"
s:"you are older than 16"
For representing" you cannot ride the roller coaster if you are under 4 feet tall unless you are older than 16 years old"
(-q) if (r unless s)
(-q) if (-s --> r)
( -s --> r ) --> (-q) is the answer I"m getting, however, in the example he replaced unless with and not and gave answer (r ^ -s ) --> -q;
Now, which is correct?