Seven people are wading in a natural pool.
The pool is clear
Not all natural pools are clear.
exists e1 s1 x1 x2.(in(e1,x2) & n_pool(x2) & a_natural(s1) & Theme(s1,x2) & Actor(e1,x1) & v_wade(e1) & n_people(x1) & card_eq_7(x1))
exists s1 x1.(n_pool(x1) & Theme(s1,x1) & a_clear(s1))