A man operating some heavy machinery.
Someone is working.
working is a rephrase of operating
exists e1 s1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_operate(e1) & n_machinery(x3) & a_heavy(s1) & Theme(s1,x3) & (x1 = x2) & n_man(x1))
exists e1 x1.(Actor(e1,x1) & v_work(e1) & n_person(x1))