The white dog is chasing a toy that is attached to a string across the grass.
A dog playing with it's owner.
The boy may not be the dog's owner.
exists e1 e2 s1 x1 x2 x3 x4 x5.(n_grass(x5) & n_dog(x1) & a_white(s1) & Theme(s1,x1) & Theme(e2,x2) & Actor(e2,x1) & v_chase(e2) & across(e1,x5) & to(e1,x4) & n_string(x4) & Theme(e1,x3) & v_attach(e1) & (x2 = x3) & n_toy(x2))
exists p1 x1 x2.(exists x3.((x1 = x3) & n_owner(x3)) & with(x1,x2) & n_thing(x2) & n_playing(x1) & of(x1,x2) & n_dog(x2))