a whole lot of people are on camels.
Some people are riding animals.
Some people could be a whole lot of people.  Camels could be animals.
exists p1 s1 x1 x2.(exists x3.(on(x1,x3) & n_camel(x3)) & of(x1,x2) & n_people(x2) & n_lot(x1) & a_whole(s1) & Theme(s1,x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_animal(x2) & n_people(x1))