Construction workers walking along train tracks.
The workers are wading in a river while fly fishing.
Train tracks and river are different.
exists e1 x1 x2 x3 x4.(along(e1,x3) & n_track(x3) & of(x3,x4) & n_train(x4) & Actor(e1,x1) & v_walk(e1) & n_worker(x1) & of(x1,x2) & n_construction(x2))
exists e1 x1 x2 x3 x4.(n_worker(x1) & while(e1,x3) & n_fishing(x3) & of(x3,x4) & n_fly(x4) & in(e1,x2) & n_river(x2) & Actor(e1,x1) & v_wade(e1))