II.2: Let L(u,v) be a predicate indicating "u likes v". Note that L is not in general symmetric. Translate the following statements into an equivalent Quantified Propositional Formulae: (a) "Some people are completely isolated - i.e., nobody likes them and they like nobody (b) "Everybody likes someone, but nobody likes everyone" (c) "Everybody is liked by someone else" (d) "Everybody likes someone who likes them back