(2) Let A,B be sets. Prove that if (A F] B)\" 2 Ac then A \\ B = :25. (3) Negate the following sentence, without using \"negative\" words (e.g. no, none, not,...). \"There is a student taking MAT 137 at UTM who has no friends whose rst name and last name beginning with P.\" (4) Given a conditional statement \"A => B" its contrapositive is the statement \"B => A\". Consider the statement: \"If it's raining, then it's cloudy.\" Its contrapositive is the statement: \"If it's not cloudy, then it's not raining.\" Explain in your own words why these two statements are equivalent to each other