city workers beside a tree grinder.
There are workers outdoors
A tree grinder is used outdoors.
exists x1 x2 x3 x4.(a_topic(x1) & beside(x1,x3) & n_grinder(x3) & of(x3,x4) & n_tree(x4) & n_worker(x1) & of(x1,x2) & n_city(x2))
exists p1 x1 x2 x3.((x1 = x2) & n_outdoors(x2) & of(x2,x3) & n_worker(x3))