People are riding around on snowmobiles.
The snow is very deep.
Not all people riding around on snowmobiles are on very deep snow.
exists e1 x1 x2.(r_around(e1) & on(e1,x2) & n_snowmobile(x2) & Actor(e1,x1) & v_ride(e1) & n_people(x1))
exists s1 x1.(n_snow(x1) & r_very(s1) & Theme(s1,x1) & a_deep(s1))