Baby sitting at a beach.
The baby is not crawling.
One who is sitting is not crawling.
exists e1 x1 x2.(ne_nam_baby(x1) & at(e1,x2) & n_beach(x2) & Actor(e1,x1) & v_sit(e1))
exists x1.(n_baby(x1) & -exists e1.(Actor(e1,x1) & v_crawl(e1)))