A young man is hard at work cleaning the floor.
A girl is mopping the kitchen floor.
A man cleaning the floor, cannot be a girl mopping the floor.
exists e1 s1 s2 x1 x2 x3 x4.(n_floor(x4) & at(s2,x2) & Theme(e1,x4) & Actor(e1,x3) & v_clean(e1) & (x2 = x3) & n_work(x2) & Theme(s2,x1) & a_hard(s2) & n_man(x1) & a_young(s1) & Theme(s1,x1))
exists e1 x1 x2 x3.(n_floor(x2) & of(x2,x3) & n_kitchen(x3) & Theme(e1,x2) & Actor(e1,x1) & v_mop(e1) & n_girl(x1))