A white dog is running around a tumbleweed on a sand dune.
The dog chases a crab on a sand dune.
Just because a dog is running around a tumbleweed on a sand dune does not mean it is chasing a crab. It may just be enjoying a nice run.
exists e1 s1 x1 x2 x3 x4.(on(e1,x3) & n_dune(x3) & of(x3,x4) & n_sand(x4) & around(e1,x2) & n_tumbleweed(x2) & Actor(e1,x1) & v_run(e1) & n_dog(x1) & a_white(s1) & Theme(s1,x1))
exists e1 x1 x2 x3 x4.(n_dog(x1) & Theme(e1,x2) & Actor(e1,x1) & v_chase(e1) & on(x2,x3) & n_dune(x3) & of(x3,x4) & n_sand(x4) & n_crab(x2))