A person sitting near the beach.
A dog is sleeping near the bench.
The subject could be either a person or a dog.
exists e1 x1 x2 x3.(n_beach(x3) & a_topic(x1) & near(e1,x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_person(x1))
exists e1 x1 x2.(n_bench(x2) & near(e1,x2) & Actor(e1,x1) & v_sleep(e1) & n_dog(x1))