Guard standing in front of concrete wall on lawn.
A guard is sitting.
Guard cannot be standing and sitting at the same time.
exists s1 x1 x2 x3 x4 x5.(a_topic(x1) & in(x1,x3) & of(x3,x4) & on(x4,x5) & n_lawn(x5) & n_wall(x4) & a_concrete(s1) & Theme(s1,x4) & n_front(x3) & n_standing(x1) & (x1 = x2) & ne_org_guard(x2))
exists e1 x1.(Actor(e1,x1) & v_sit(e1) & n_guard(x1))