African people walk by a teal colored building in the desert.
German people sitting by a building in the desert.
German and African people are different nationalities.  A person cannot be sitting if they walk.
exists e1 s1 s2 s3 x1 x2 x3 x4.(n_desert(x4) & a_topic(x1) & Actor(e1,x3) & in(x3,x4) & n_building(x3) & a_colored(s3) & Theme(s3,x3) & a_teal(s2) & Theme(s2,x3) & Theme(e1,x2) & v_walk(e1) & (x1 = x2) & n_people(x1) & a_african(s1) & Theme(s1,x1))
exists e1 s1 x1 x2 x3 x4.(n_desert(x4) & a_topic(x1) & by(e1,x3) & in(x3,x4) & n_building(x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_people(x1) & a_german(s1) & Theme(s1,x1))