A crowd of people walking down the middle of a city street.
The group are walking down the street to the cabs.
People can walk down the street for other reasons than cabs.
exists e1 s1 x1 x2 x3 x4 x5 x6.(n_middle(x4) & a_topic(x1) & of(x1,x2) & a_down(s1) & Manner(e1,s1) & Theme(e1,x4) & Actor(e1,x3) & v_walk(e1) & of(x4,x5) & n_street(x5) & of(x5,x6) & n_city(x6) & (x2 = x3) & n_people(x2) & n_crowd(x1))
exists e1 x1 x2 x3.(n_cab(x3) & n_street(x2) & n_group(x1) & to(e1,x3) & down(e1,x2) & Actor(e1,x1) & v_walk(e1))