A man is working on a steam engine in front of a water tower.
The man is a mechanic.
Not all men are a mechanic.
exists e1 x1 x2 x3 x4 x5 x6.(in(e1,x4) & of(x4,x5) & n_tower(x5) & of(x5,x6) & n_water(x6) & n_front(x4) & on(e1,x2) & n_engine(x2) & of(x2,x3) & n_steam(x3) & Actor(e1,x1) & v_work(e1) & n_man(x1))
exists p1 x1.(n_man(x1) & exists x2.((x1 = x2) & n_mechanic(x2)))