A woman is riding a blue bike.
The woman is riding a black skateboard.
Person riding a bike can not ride skateboard at the same time.
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bike(x2) & a_blue(s1) & Theme(s1,x2) & n_woman(x1))
exists e1 s1 x1 x2.(n_woman(x1) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_skateboard(x2) & a_black(s1) & Theme(s1,x2))