People are playing water volleyball.
There are people playing with a ball.
in a both sentence water and playing is various
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_volleyball(x2) & of(x2,x3) & n_water(x3) & n_people(x1))
exists p1 x1 e1 x2 x3 x4.((x1 = x2) & with(e1,x4) & n_ball(x4) & Actor(e1,x3) & v_play(e1) & (x2 = x3) & n_people(x2))