Teenage boy riding a bicycle through a grassy field.
A boy rides a skateboard on a sidewalk
A bicycle is different from a skateboard. A grassy filed would not be on a sidewalk.
exists e1 s1 x1 x2 x3 x4 x5.(a_topic(x1) & through(e1,x5) & n_field(x5) & a_grassy(s1) & Theme(s1,x5) & Theme(e1,x4) & Actor(e1,x3) & v_ride(e1) & n_bicycle(x4) & (x1 = x3) & n_boy(x1) & of(x1,x2) & n_teenage(x2))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & on(x2,x3) & n_sidewalk(x3) & n_skateboard(x2) & n_boy(x1))