A skateboarder at night on a ramp.
The skateboarder is sitting
The skateboarder is either sitting or on the ramp.
exists x1 x2 x3.(a_topic(x1) & at(x1,x2) & on(x2,x3) & n_ramp(x3) & n_night(x2) & n_skateboarder(x1))
exists e1 x1.(n_skateboarder(x1) & Actor(e1,x1) & v_sit(e1))