A man riding a BMX bike is attempting a bicycle trick in a skate park.
The man is a professional bmx bikers.
Not all men attempting a BMX bike trick are a professional.
exists e1 e2 x1 x2 x3 x4 x5 x6 x7 x8.(in(e2,x7) & n_park(x7) & of(x7,x8) & n_skate(x8) & Theme(e2,x5) & Actor(e2,x1) & v_attempt(e2) & n_trick(x5) & of(x5,x6) & n_bicycle(x6) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_bike(x3) & (x3 = x4) & ne_org_bmx(x4) & (x1 = x2) & n_man(x1))
exists p1 x1.(n_man(x1) & exists s1 x2 x3.((x1 = x2) & n_biker(x2) & of(x2,x3) & n_bmx(x3) & a_professional(s1) & Theme(s1,x2)))