Border Collies at herding a competition.
dogs are at a competition on christmas
Not all competitions are on christmas.
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x4) & Actor(e1,x3) & v_herd(e1) & n_competition(x4) & (x1 = x3) & n_collie(x1) & (x1 = x2) & ne_nam_border(x2))
exists p1 x1.(exists x2 x3.(at(x1,x2) & on(x2,x3) & n_christmas(x3) & n_competition(x2)) & n_dog(x1))