A woman and child are on their way to play tennis.
A woman and child walking.
On their way could mean that they are walking.
exists p1 x1 x2 x3 x4.(exists p2.(on(x1,x4) & Topic(x4,p2) & exists e1 x5.(Theme(e1,x5) & Actor(e1,x4) & v_play(e1) & n_tennis(x5))) & n_way(x4) & of(x4,x2) & n_thing(x2) & n_child(x3) & n_woman(x2) & subset_of(x3,x1) & subset_of(x2,x1))
exists s1 x1 x2 x3.(a_topic(s1) & subset_of(x2,s1) & n_walking(x2) & of(x2,x3) & n_child(x3) & subset_of(x1,s1) & n_woman(x1))