Translate the following inference to logic notation: For all x, if x_12 were a janitor, then x_12 is reading a book. If Linda reads a book, then Barbara is running. If Barbara goes running, then Linda is reading a book. Barbara is not running. Therefore Linda is not a janitor.
forall x: P(x) -> Q(x). Q(a) -> p. p -> Q(a). ~p. Therefore ~P(a).