Biker doing a trick in air.
The biker is sitting.
Biker is either sitting or doing a trick.
exists e1 x1 x2 x3.(ne_nam_biker(x1) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & in(x2,x3) & n_air(x3) & n_trick(x2))
exists e1 x1.(n_biker(x1) & Actor(e1,x1) & v_sit(e1))