A construction worker operates heavy machinery, presumably a crane.
A worker is eating lunch.
A worker would not be eating lunch and operating machinery at the same time.
exists e1 s1 x1 x2 x3 x4.(Theme(e1,x3) & Actor(e1,x1) & v_operate(e1) & rel(x3,x4) & r_presumably(x4) & n_crane(x4) & n_machinery(x3) & a_heavy(s1) & Theme(s1,x3) & n_worker(x1) & of(x1,x2) & n_construction(x2))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_eat(e1) & n_lunch(x2) & n_worker(x1))