A wrecked ambulance is being towed.
There is a vehicle that is being towed.
A wrecked ambulance is still a vehicle.
exists e1 s1 x1.(Theme(e1,x1) & v_tow(e1) & n_ambulance(x1) & a_wrecked(s1) & Theme(s1,x1))
exists p1 x1 e1 x2 x3.((x1 = x2) & Theme(e1,x3) & v_tow(e1) & (x2 = x3) & n_vehicle(x2))