There is a red truck behind the horses.
The horses are close by vehicles.
If there is a red truck behind the horses then the horses are obviously close by vehicles.
exists p1 x1 x3.(n_horse(x3) & exists s1 x2.((x1 = x2) & behind(x2,x3) & n_truck(x2) & a_red(s1) & Theme(s1,x2)))
exists s1 x1 x2.(n_horse(x1) & by(s1,x2) & n_vehicle(x2) & Theme(s1,x1) & a_close(s1))