(Predicate Logic)

Simon says: Horses cannot fly and, if pigs can sing, then either horses can fly or elephants can dance. 1 Why 3 is the minimum number of propositional variables needed to express an equivalent statement to Simons in propositional logic? 2 Express Simons statement as a compound proposition by writing down all atomic propositions, their corresponding letters, and the compound statement that represents what Simon says. 3 Under what conditions would Simon be telling the truth?