Construction workers working on a building.
Some people are sitting and having lunch.
You can not be working and sitting at the same time.
exists e1 x1 x2 x3.(on(e1,x3) & n_building(x3) & Actor(e1,x1) & v_work(e1) & n_worker(x1) & of(x1,x2) & n_construction(x2))
exists e1 e2 x1 x2 x3.(Theme(e2,x3) & Actor(e2,x2) & v_have(e2) & n_lunch(x3) & n_people(x2) & Actor(e1,x1) & v_sit(e1) & n_people(x1))