People walking on a desert street.
Everybody is walking.
Just because some people are walking doesn't mean everybody is walking.
exists e1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x3) & n_street(x3) & of(x3,x4) & n_desert(x4) & Actor(e1,x2) & v_walk(e1) & (x1 = x2) & n_people(x1))
all x1.(n_person(x1) -> exists e1.(Actor(e1,x1) & v_walk(e1)))