Three people are on a sidewalk.
Three friends are walking.
The three people walking on the sidewalk are friends.
exists p1 x1.(exists x2.(on(x1,x2) & n_sidewalk(x2)) & n_people(x1) & card_eq_3(x1))
exists e1 x1.(Actor(e1,x1) & v_walk(e1) & n_friend(x1) & card_eq_3(x1))