A crowd of black people are gathered and one person has a backpack on.
A crowd of teenage black people are waiting for the school to open and one of them has a backpack.
Not all crowds of people are teenage, and not all of them are waiting for the school to open.
exists e1 e2 s1 s2 x1 x2 x3 x4.(a_on(s2) & Manner(e2,s2) & Theme(e2,x4) & Actor(e2,x3) & v_have(e2) & n_backpack(x4) & n_person(x3) & card_eq_1(x3) & Theme(e1,x1) & v_gather(e1) & of(x1,x2) & n_people(x2) & a_black(s1) & Theme(s1,x2) & n_crowd(x1))
exists e1 e2 p1 s1 s2 x1 x2 x3 x4 x5.(n_school(x5) & Theme(e2,x4) & Actor(e2,x3) & v_have(e2) & n_backpack(x4) & of(x3,x1) & n_thing(x1) & n_thing(x3) & card_eq_1(x3) & Topic(e1,p1) & Actor(e1,x1) & v_wait(e1) & exists e3.(Actor(e3,x5) & v_open(e3)) & of(x1,x2) & n_people(x2) & a_black(s2) & Theme(s2,x2) & a_teenage(s1) & Theme(s1,x2) & n_crowd(x1))