Several children are playing soccer in a field.
Nobody is playing.
Either children are playing or nobody is playing but not both at the same time.
exists e1 s1 x1 x2 x3.(in(e1,x3) & n_field(x3) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_soccer(x2) & n_child(x1) & a_several(s1) & Theme(s1,x1))
-exists e1 x1.(Actor(e1,x1) & v_play(e1) & n_person(x1))