The trailer is white
The trailer is hitched to a truck
Not all white trailers are hitched to a truck
exists s1 x1.(n_trailer(x1) & Theme(s1,x1) & a_white(s1))
exists e1 x1 x2.(n_trailer(x1) & to(e1,x2) & n_truck(x2) & Theme(e1,x1) & v_hitch(e1))