The windows of the building are barred.
The windows of the building are barred for protection.
The windows could be barred to keep prisoners in instead of for protection.
exists e1 x1 x2.(n_building(x2) & n_window(x1) & Theme(e1,x1) & v_bar(e1) & of(x1,x2))
exists e1 x1 x2 x3.(n_building(x2) & n_window(x1) & for(e1,x3) & n_protection(x3) & Theme(e1,x1) & v_bar(e1) & of(x1,x2))