A guy on a skateboard does a trick on a ramp while others watch on the other side of the ramp.
The skateboarder is alone at the park.
The skateboarder is either alone or with others.
exists e1 p1 x1 x2 x3 x4 x6.(-(x6 = x6) & n_side(x6) & exists e2 x5.(on(e2,x6) & of(x6,x4) & Actor(e2,x5) & v_watch(e2) & -(x5 = x1) & n_person(x5)) & n_ramp(x4) & n_ramp(x4) & n_person(x1) & while(e1,p1) & on(e1,x4) & Theme(e1,x3) & Actor(e1,x1) & v_do(e1) & n_trick(x3) & on(x1,x2) & n_skateboard(x2) & n_guy(x1))
exists s1 x1 x2.(n_park(x2) & n_skateboarder(x1) & at(s1,x2) & Theme(s1,x1) & a_alone(s1))