Some cows cluster together.
Some are horses in the field.
Cows are not horses.
exists e1 p1 x1.(exists s1.(Theme(s1,x1) & a_together(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_cluster(e1) & n_cow(x1))
exists p1 x1 x3.(n_field(x3) & exists x2.((x1 = x2) & in(x2,x3) & n_horse(x2)) & n_thing(x1))