A traveling boy looks sad.
the boy is happy
Either he is happy or sad.
exists e2 e1 p1 x1.(exists s1.(Theme(s1,x1) & a_sad(s1)) & Topic(e2,p1) & Actor(e2,x1) & v_look(e2) & n_boy(x1) & Actor(e1,x1) & v_travel(e1))
exists s1 x1.(n_boy(x1) & Theme(s1,x1) & a_happy(s1))