(<=> (Rational-Number ?X) (And (Real-Number ?X) (Exists (?Y) (And (Integer ?Y) (Integer (* ?X ?Y))))))
(Exists (?Y) (And (Integer ?Y) (Integer (* ?X ?Y)))) (Real-Number ?X)
(<=> (Rational-Number ?X) (And (Real-Number ?X) (Exists (?Y) (And (Integer ?Y) (Integer (* ?X ?Y))))))