Dancers a standing on a sidewalk.
Some dancers are waiting for the bus.
standing on a sidewalk doesn't always mean  waiting for the bus.
all x1.(n_standing(x1) -> exists x2 x3.(a_topic(x2) & on(x2,x3) & n_sidewalk(x3) & for(x2,x1) & n_dancer(x2)))
exists e1 x1 x2.(n_bus(x2) & for(e1,x2) & Actor(e1,x1) & v_wait(e1) & n_dancer(x1))