A woman and a child are walking on a beach.
The woman is riding a horse on the beach.
One is either walking or riding, not both.
exists e1 x1 x2 x3 x4.(on(e1,x4) & n_beach(x4) & Actor(e1,x1) & v_walk(e1) & subset_of(x3,x1) & n_child(x3) & subset_of(x2,x1) & n_woman(x2))
exists e1 x1 x2 x3.(n_beach(x3) & n_woman(x1) & on(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_horse(x2))