A bulldozer is working on a building.
There is a parrot in a cage.
A parrot is not a bulldozer.
exists e1 x1 x2.(on(e1,x2) & n_building(x2) & Actor(e1,x1) & v_work(e1) & n_bulldozer(x1))
exists p1 x1 x2 x3.((x1 = x2) & in(x2,x3) & n_cage(x3) & n_parrot(x2))