a skateboarder does manuals on a bench.
A skateboarder is riding a motorcycle.
The skateboarder cannot be doing manuals and riding a motorcycle at the same time.
exists e1 x1 x2 x3.(on(e1,x3) & n_bench(x3) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & n_manual(x2) & n_skateboarder(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_motorcycle(x2) & n_skateboarder(x1))