The person is standing in the boat.
The yacht contains a man
Not all boats are yachts and not all people are man. They could be any kind of people with any kind of person on it.
exists e1 x1 x2.(n_boat(x2) & n_person(x1) & in(e1,x2) & Actor(e1,x1) & v_stand(e1))
exists e1 x1 x2.(n_yacht(x1) & Theme(e1,x2) & Actor(e1,x1) & v_contain(e1) & n_man(x2))