A crowd of black people are gathered and one person has a backpack on.
A white man stands by himself.
A white man cannot be part of a crowd of black people, and be by himself.
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 s1 x1 x2.(a_topic(x1) & by(x1,x2) & n_male(x2) & n_stand(x1) & of(x1,x2) & n_man(x2) & a_white(s1) & Theme(s1,x1))