A person on a bike in the air over a ramp.
A boy on a bike in the air over a ramp.
Not every person that rides a bike in the air is a boy.
exists x1 x2 x3 x4.(n_air(x3) & a_topic(x1) & over(x1,x4) & n_ramp(x4) & on(x1,x2) & in(x2,x3) & n_bike(x2) & n_person(x1))
exists x1 x2 x3 x4.(n_air(x3) & a_topic(x1) & on(x1,x2) & in(x2,x3) & over(x3,x4) & n_ramp(x4) & n_bike(x2) & n_boy(x1))