Parents with young children sitting at a picnic table.
Nobody is sitting.
People cannot be both sitting and not sitting.
exists e1 s1 x1 x2 x3 x4 x5.(a_topic(x1) & with(x1,x2) & at(e1,x4) & n_table(x4) & of(x4,x5) & n_picnic(x5) & Actor(e1,x3) & v_sit(e1) & (x2 = x3) & n_child(x2) & a_young(s1) & Theme(s1,x2) & n_parent(x1))
-exists e1 x1.(Actor(e1,x1) & v_sit(e1) & n_person(x1))