A young man stands on a roof.
A person on a roof.
A young man is a person.
exists e1 s1 x1 x2.(on(e1,x2) & n_roof(x2) & Actor(e1,x1) & v_stand(e1) & n_man(x1) & a_young(s1) & Theme(s1,x1))
exists x1 x2.(a_topic(x1) & on(x1,x2) & n_roof(x2) & n_person(x1))