The black and white dog leaps to catch a toy.
A dog is catching a ball.
A toy could be many different things, you cannot infer it is a ball.
exists e1 p1 s1 s2 x1.(n_dog(x1) & a_white(s2) & Theme(s2,x1) & a_black(s1) & Theme(s1,x1) & Topic(e1,p1) & Actor(e1,x1) & v_leap(e1) & exists e2 x2.(Theme(e2,x2) & Actor(e2,x1) & v_catch(e2) & n_toy(x2)))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_catch(e1) & n_ball(x2) & n_dog(x1))