A person walking with a dog.
A man walks with his dog.
The person is not necessarily a man. The dog is not necessarily his.
exists x1 x2 x3.(a_topic(x1) & with(x1,x3) & n_dog(x3) & Time(x1,x2) & n_walking(x2) & n_person(x1))
exists e1 x1 x2.(with(e1,x2) & n_dog(x2) & of(x2,x1) & n_male(x1) & Actor(e1,x1) & v_walk(e1) & n_man(x1))