A baby crawls at a playground.
An infant is at a playground.
infant refers to baby
exists e1 x1 x2.(at(e1,x2) & n_playground(x2) & Actor(e1,x1) & v_crawl(e1) & n_baby(x1))
exists p1 x1.(exists x2.(at(x1,x2) & n_playground(x2)) & n_infant(x1))