The boy is playing in the sand.
The boy is playing catch.
The boy is either playing catch or playing with the sand.
exists e1 x1 x2.(n_sand(x2) & n_boy(x1) & in(e1,x2) & Actor(e1,x1) & v_play(e1))
exists e1 x1 x2.(n_boy(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_catch(x2))