An old man is showing a young boy a washer while they are repairing something.
The two teenagers sing a song while sitting on the ground.
Singing and sitting teenagers cannot simultaneously be an old man and young boy repairing something,
exists s1 x1.(all x2.(n_washer(x2) -> exists e1 p1 s2 x3.(exists e2 x4.(Theme(e2,x4) & Actor(e2,x1) & v_repair(e2) & n_thing(x4)) & while(e1,p1) & Theme(e1,x3) & Actor(e1,x1) & v_show(e1) & for(x3,x2) & n_boy(x3) & a_young(s2) & Theme(s2,x3))) & n_thing(x1) & n_man(x1) & a_old(s1) & Theme(s1,x1))
exists e2 e1 x1 x2 x3.(n_ground(x3) & n_teenager(x1) & card_eq_2(x1) & while(e1,e2) & on(e2,x3) & Actor(e2,x1) & v_sit(e2) & Theme(e1,x2) & Actor(e1,x1) & v_sing(e1) & n_song(x2))