Looking outside at a waiter serving some customers.
The waiter dropped his tray.
Dropped and serving are different types of words.
exists e1 e2 x1 x2 x3 x4 x5.(at(e1,x3) & Theme(e2,x5) & Actor(e2,x4) & v_serve(e2) & n_customer(x5) & (x3 = x4) & n_waiter(x3) & Theme(e1,x2) & Actor(e1,x1) & v_look(e1) & n_outside(x2) & n_thing(x1))
exists e1 x1 x2.(n_tray(x2) & of(x2,x1) & n_male(x1) & n_waiter(x1) & Theme(e1,x2) & Actor(e1,x1) & v_drop(e1))