A city block is sealed off by the police.
There are no detours today.
If the block is sealed off then there must be some kind of detour.
exists e1 s1 x1 x2 x3.(n_police(x3) & Actor(e1,x3) & a_off(s1) & Manner(e1,s1) & Theme(e1,x1) & v_seal(e1) & n_block(x1) & of(x1,x2) & n_city(x2))
exists p1 x1 x2.(Time(p1,x2) & n_today(x2) & -exists x3.((x1 = x3) & n_detour(x3)))