Cheerleaders are on the field cheering.
An empty field.
There cannot be an empty field while there are cheerleaders on it.
exists p1 x1 x2 x3.(n_cheering(x2) & of(x2,x3) & n_field(x3) & on(x1,x2) & n_cheerleader(x1))
exists s1 x1.(a_topic(x1) & n_field(x1) & a_empty(s1) & Theme(s1,x1))