A green motorcycle is being ridden on a wet racetrack.
There is a green motorcycle racing other motorcycles.
A motorcycle on a racetrack is not necessarily implied to be racing other motorcycles.
exists e1 s1 s2 x1 x2.(on(e1,x2) & n_racetrack(x2) & a_wet(s2) & Theme(s2,x2) & Theme(e1,x1) & v_ride(e1) & n_motorcycle(x1) & a_green(s1) & Theme(s1,x1))
exists p1 x1 e1 s1 x2 x3 x4.((x1 = x2) & Theme(e1,x4) & Actor(e1,x3) & v_race(e1) & -(x4 = x2) & n_motorcycle(x2) & n_motorcycle(x2) & n_motorcycle(x4) & (x2 = x3) & a_green(s1) & Theme(s1,x2))