a butcher cutting fish to be sold at the market
Nobody is cutting fish.
The butcher is cutting fish as opposed to nobody cutting fish.
exists e1 p1 x1 x2 x3 x4 x5.(n_market(x5) & a_topic(x1) & Topic(e1,p1) & exists e2.(at(e2,x5) & Theme(e2,x2) & v_sell(e2)) & Theme(e1,x4) & Actor(e1,x3) & v_cut(e1) & n_fish(x4) & (x1 = x3) & (x1 = x2) & n_butcher(x1))
-exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_cut(e1) & n_fish(x2) & n_person(x1))