A person rides a sled over several people.
A man rode a snowmobile over a group of kids.
A person either rides a sled or a snowmobile.
exists e1 s1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & over(x2,x3) & n_people(x3) & a_several(s1) & Theme(s1,x3) & n_sled(x2) & n_person(x1))
exists e1 x1 x2 x3 x4.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & over(x2,x3) & of(x3,x4) & n_kid(x4) & n_group(x3) & n_snowmobile(x2) & n_man(x1))