A person is jumping using rollerblades.
The person is riding a horse.
One does not wear rollerblades while riding a horse.
exists e2 e1 x1 x2.(for(e1,e2) & Theme(e2,x2) & Actor(e2,x1) & v_use(e2) & n_rollerblade(x2) & Actor(e1,x1) & v_jump(e1) & n_person(x1))
exists e1 x1 x2.(n_person(x1) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_horse(x2))