Two children are sliding down a water slide.
The water slide is tall.
the water slide is not necessarily tall.
exists e1 s1 x1 x2 x3.(a_down(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_slide(e1) & n_slide(x2) & of(x2,x3) & n_water(x3) & n_child(x1) & card_eq_2(x1))
exists s1 x1 x2.(n_slide(x1) & of(x1,x2) & n_water(x2) & Theme(s1,x1) & a_tall(s1))