The horse on the right is red.
The horse on the right is yellow.
The horse cannot be red and yellow at the same time.
exists s1 x1 x2.(n_right(x2) & n_horse(x1) & Theme(s1,x1) & a_red(s1) & on(x1,x2))
exists s1 x1 x2.(n_right(x2) & n_horse(x1) & Theme(s1,x1) & a_yellow(s1) & on(x1,x2))