Toddler sits on a pile of rocks.
The toddler is crawling in the grass.
The toddler cannot be crawling and sitting at the same time
exists e1 x1 x2 x3.(ne_nam_toddler(x1) & on(e1,x2) & of(x2,x3) & n_rock(x3) & n_pile(x2) & Actor(e1,x1) & v_sit(e1))
exists e1 x1 x2.(n_grass(x2) & n_toddler(x1) & in(e1,x2) & Actor(e1,x1) & v_crawl(e1))