A girl and boy sit on a fence.
Children sit on a fence.
Both subjects sit on a fence
exists e1 x1 x2 x3 x4.(on(e1,x4) & n_fence(x4) & Actor(e1,x1) & v_sit(e1) & n_boy(x3) & n_girl(x2) & subset_of(x3,x1) & subset_of(x2,x1))
exists e1 x1 x2.(on(e1,x2) & n_fence(x2) & Actor(e1,x1) & v_sit(e1) & n_child(x1))