People are upside-down on a roller coaster.
A family is walking through a field.
Upside-down is different than walking.
exists s1 x1 x2 x3.(on(s1,x2) & n_coaster(x2) & of(x2,x3) & n_roller(x3) & Theme(s1,x1) & a_upside-down(s1) & n_people(x1))
exists e1 x1 x2.(through(e1,x2) & n_field(x2) & Actor(e1,x1) & v_walk(e1) & n_family(x1))