A bicycler does tricks under an overpass.
A young man on a bike practices tricks under a highway bridge
Not every bicycle rider is a young man and not every overpass is a highway bridge.
exists e1 x1 x2 x3.(under(e1,x3) & n_overpass(x3) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & n_trick(x2) & n_bicycler(x1))
exists s1 x1 x2 x3 x4 x5 x6.(a_topic(x1) & on(x1,x2) & under(x2,x5) & n_bridge(x5) & of(x5,x6) & n_highway(x6) & Time(x2,x4) & n_trick(x4) & n_practice(x2) & of(x2,x3) & n_bike(x3) & n_man(x1) & a_young(s1) & Theme(s1,x1))