A skateboarder jumps another skateboard.
A skateboarder is practicing in a skate park.
Not all skateboarders go to a skate park.
exists e1 x1 x2 x3.(n_skateboard(x2) & Theme(e1,x3) & Actor(e1,x1) & v_jump(e1) & n_skateboard(x3) & -(x3 = x2) & n_skateboarder(x1))
exists e1 x1 x2 x3.(in(e1,x2) & n_park(x2) & of(x2,x3) & n_skate(x3) & Actor(e1,x1) & v_practice(e1) & n_skateboarder(x1))