There are a lot of kids walking on train tracks surrounded by trees.
a couple was there
A lot of kids is the same as a couple.
exists p1 x1 e2 e1 x2 x3 x4 x5 x6 x7 x8.((x1 = x2) & of(x2,x3) & on(e1,x5) & Actor(e2,x8) & n_tree(x8) & Theme(e2,x7) & v_surround(e2) & (x5 = x7) & n_track(x5) & of(x5,x6) & n_train(x6) & Actor(e1,x4) & v_walk(e1) & (x3 = x4) & n_kid(x3) & n_lot(x2))
exists s1 x1.(Theme(s1,x1) & a_there(s1) & n_couple(x1))