A brown dog digs in the sand for an orange ball.
A black dog digs in the dirt for an blue chew toy.
When a brown dog digs for an orange ball, black one looks for an blue chew toy.
exists s1 x1 x2 x3 x4 x5.(n_sand(x3) & a_topic(x1) & in(x1,x3) & for(x3,x4) & n_ball(x4) & of(x4,x5) & n_orange(x5) & n_dig(x1) & of(x1,x2) & n_dog(x2) & a_brown(s1) & Theme(s1,x1))
exists e1 s1 x1 x2 x3 x4 x5.(n_dirt(x3) & Theme(e1,x5) & Actor(e1,x1) & v_chew(e1) & n_toy(x5) & in(x1,x3) & for(x3,x4) & n_blue(x4) & n_dig(x1) & of(x1,x2) & n_dog(x2) & a_black(s1) & Theme(s1,x1))