A child jumps on a sand dune.
A boy is jumping on a hill covered in sand.
There is nothing to suggest the child is a boy.
exists e1 x1 x2 x3.(on(e1,x2) & n_dune(x2) & of(x2,x3) & n_sand(x3) & Actor(e1,x1) & v_jump(e1) & n_child(x1))
exists e1 e2 x1 x2 x3 x4.(on(e1,x2) & in(e2,x4) & n_sand(x4) & Theme(e2,x3) & v_cover(e2) & (x2 = x3) & n_hill(x2) & Actor(e1,x1) & v_jump(e1) & n_boy(x1))