The horse on the left has white markings.
The horse is mottled with white and brown.
White markings does not necessarily mean mottled with white and brown.
exists e1 s1 x1 x2 x3.(n_left(x2) & n_horse(x1) & Theme(e1,x3) & Actor(e1,x1) & v_have(e1) & n_marking(x3) & a_white(s1) & Theme(s1,x3) & on(x1,x2))
exists e1 s1 x1 x2.(n_horse(x1) & with(e1,x2) & n_brown(x2) & a_white(s1) & Theme(s1,x2) & Theme(e1,x1) & v_mottle(e1))