A child skis across the snowy ground.
A father teaching his child how to ski.
The child could be by himself with no father teaching him.
exists e1 s1 x1 x2.(n_ground(x2) & a_snowy(s1) & Theme(s1,x2) & across(e1,x2) & Actor(e1,x1) & v_ski(e1) & n_child(x1))
exists e1 p1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_teach(e1) & Topic(x3,p1) & exists e2.(Actor(e2,x3) & v_ski(e2)) & n_child(x3) & of(x3,x1) & n_male(x1) & (x1 = x2) & n_father(x1))