A man and woman fishing at the beach.
The man and women are trying to catch a shark.
Just because two people are fishing it does not mean that they are trying to catch a shark. They could be trying to catch some other type of fish.
exists s1 x1 x2 x3 x4.(n_beach(x4) & a_topic(s1) & subset_of(x2,s1) & at(x2,x4) & n_fishing(x2) & of(x2,x3) & n_woman(x3) & subset_of(x1,s1) & n_man(x1))
exists e1 p1 x1 x2 x3.(n_man(x2) & Topic(e1,p1) & Actor(e1,x1) & v_try(e1) & exists e2 x4.(Theme(e2,x4) & Actor(e2,x1) & v_catch(e2) & n_shark(x4)) & subset_of(x3,x1) & n_woman(x3) & subset_of(x2,x1))