The small boy is running and smiling.
a little girl is standing on a sidewalk.
The child is either a boy or a girl, not both. The small person is either running or standing, not both.
exists e2 e1 s1 s2 x1.(n_boy(x1) & a_small(s2) & Theme(s2,x1) & a_small(s1) & Theme(s1,x1) & Actor(e2,x1) & v_smile(e2) & Actor(e1,x1) & v_run(e1))
exists e1 s1 x1 x2.(on(e1,x2) & n_sidewalk(x2) & Actor(e1,x1) & v_stand(e1) & n_girl(x1) & a_little(s1) & Theme(s1,x1))