A construction worker observes his equipment.
The worker is sleeping.
A worker can not both be sleeping and observing his equipment at the same time.
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_observe(e1) & n_equipment(x3) & of(x3,x1) & n_male(x1) & n_worker(x1) & of(x1,x2) & n_construction(x2))
exists e1 x1.(n_worker(x1) & Actor(e1,x1) & v_sleep(e1))