Young children on a sled are being pulled through the snow.
A boy and a girl on a sled are being pulled through the snow by an adult.
Young children does not necessarily imply a boy and a girl and children being pulled in a sled does not imply being pulled by an adult.
exists e1 s1 x1 x2 x3.(n_snow(x3) & through(e1,x3) & Theme(e1,x1) & v_pull(e1) & on(x1,x2) & n_sled(x2) & n_child(x1) & a_young(s1) & Theme(s1,x1))
exists e1 x1 x2 x3 x4 x5 x6.(n_snow(x5) & Actor(e1,x6) & n_adult(x6) & through(e1,x5) & Theme(e1,x1) & v_pull(e1) & subset_of(x3,x1) & on(x3,x4) & n_sled(x4) & n_girl(x3) & subset_of(x2,x1) & n_boy(x2))