A city block is sealed off by the police.
People can not access the city block.
Just because a city block is sealed off by the police does not mean that people can not access the city block.
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 x1 x2 x3.(n_block(x2) & of(x2,x3) & n_city(x3) & -exists e1 p1.(exists e2.(Theme(e2,x2) & Actor(e2,x1) & v_access(e2)) & Topic(e1,p1) & Actor(e1,x1) & v_can(e1)) & n_people(x1))