The two people are lying in gray rocks.
Two people are lying in rocks.
lying in gray rocks  can also be said as  people are lying in rocks.
exists e1 s1 x1 x2.(n_people(x1) & card_eq_2(x1) & in(e1,x2) & n_rock(x2) & a_gray(s1) & Theme(s1,x2) & Actor(e1,x1) & v_lie(e1))
exists e1 x1 x2.(in(e1,x2) & n_rock(x2) & Actor(e1,x1) & v_lie(e1) & n_people(x1) & card_eq_2(x1))