Hard hat workers are descending into cement walls.
The workers in hard hats are mowing the grass.
grass  is not the same as  cement
exists e1 x1 x2 x3 x4 x5.(into(e1,x4) & n_wall(x4) & of(x4,x5) & n_cement(x5) & Actor(e1,x1) & v_descend(e1) & n_worker(x1) & of(x1,x3) & n_hat(x3) & (x1 = x2) & ne_nam_hard(x2))
exists e1 s1 x1 x2 x3.(n_grass(x3) & n_worker(x1) & Theme(e1,x3) & Actor(e1,x1) & v_mow(e1) & in(x1,x2) & n_hat(x2) & a_hard(s1) & Theme(s1,x2))