Translate the following inference to logic notation: If Susan were a writer, then David is running. David is not running. Joseph is a politician if and only if Susan is a writer. For all x, y_1 is a politician or y_1 will read a book. Therefore Joseph is reading a book.
p -> q. ~q. P(a) <-> p. forall x: P(x) or Q(x). Therefore Q(a).