Man sitting on a can in the street.
A boy riding a tractor.
A boy is not a man and a can is not a tractor.
exists e1 x1 x2 x3 x4.(n_street(x4) & a_topic(x1) & on(e1,x3) & in(x3,x4) & n_can(x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_man(x1))
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_tractor(x3) & (x1 = x2) & n_boy(x1))