Everyone in this picture is wearing black.
People are wearing black.
If everyone is wearing black then there are people wearing black.
exists x2.(n_picture(x2) & all x1.(n_person(x1) -> exists e1 p1.(exists s1.(Theme(s1,x1) & a_black(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_wear(e1) & in(x1,x2))))
exists e1 p1 x1.(exists s1.(Theme(s1,x1) & a_black(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_wear(e1) & n_people(x1))