An adult and a child sitting on a police motorcycle.
There is a man and a boy sitting on a motorcycle.
just because an adult and a child sitting are on a police motorcycle doesn't mean a man and a boy sitting on a motorcycle
exists e1 s1 x1 x2 x3 x4 x5.(a_topic(s1) & subset_of(x2,s1) & on(e1,x4) & n_motorcycle(x4) & of(x4,x5) & n_police(x5) & Actor(e1,x3) & v_sit(e1) & (x2 = x3) & n_child(x2) & subset_of(x1,s1) & n_adult(x1))
exists p1 x1 e1 x2 x3 x4 x5 x6.((x1 = x2) & subset_of(x4,x2) & on(e1,x6) & n_motorcycle(x6) & Actor(e1,x5) & v_sit(e1) & (x4 = x5) & n_boy(x4) & subset_of(x3,x2) & n_man(x3))