A tribe of people are posing for a picture.
Some humans posing
Humans are people and they are posing for a picture.
exists e1 x1 x2 x3.(for(e1,x3) & n_picture(x3) & Actor(e1,x1) & v_pose(e1) & of(x1,x2) & n_people(x2) & n_tribe(x1))
exists e1 x1 x2.(a_topic(x1) & Actor(e1,x2) & v_pose(e1) & (x1 = x2) & n_human(x1))