A little boy and a little girl are playing with pebbles on the beach.
The children are playing with pebbles in the sand at the beach.
Where there are pebbles and beaches there is not necessarily sand.
exists e1 s1 s2 x1 x2 x3 x4 x5.(n_beach(x5) & on(e1,x5) & with(e1,x4) & n_pebble(x4) & Actor(e1,x1) & v_play(e1) & subset_of(x3,x1) & n_girl(x3) & a_little(s2) & Theme(s2,x3) & subset_of(x2,x1) & n_boy(x2) & a_little(s1) & Theme(s1,x2))
exists e1 x1 x2 x3 x4.(n_beach(x4) & n_sand(x3) & n_child(x1) & at(e1,x4) & in(e1,x3) & with(e1,x2) & n_pebble(x2) & Actor(e1,x1) & v_play(e1))