People are riding around on snowmobiles.
The snowmobiles are parked until winter
A snowmobile cannot be parked and rode at the same time.
exists e1 x1 x2.(r_around(e1) & on(e1,x2) & n_snowmobile(x2) & Actor(e1,x1) & v_ride(e1) & n_people(x1))
exists e1 x1 x2.(n_snowmobile(x1) & until(e1,x2) & n_winter(x2) & Theme(e1,x1) & v_park(e1))