A boy wearing sunglasses looks straight ahead.
The boy is at the beach.
The fact that a boy looks straight ahead doesn't imply that he is at the beach.
exists e2 e1 p1 s1 x1 x2 x3.(a_ahead(s1) & Manner(e2,s1) & exists s2.(Theme(s2,x1) & a_straight(s2)) & Topic(e2,p1) & Actor(e2,x1) & v_look(e2) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_sunglass(x3) & (x1 = x2) & n_boy(x1))
exists p1 x1 x2.(n_beach(x2) & n_boy(x1) & at(x1,x2))