One boy hoists another boy up on his back.
Two boys are friends.
Just because two boys are on his bank doesn't mean they are friends
exists e1 s1 x1 x2 x3.(on(e1,x3) & n_back(x3) & of(x3,x2) & n_male(x2) & a_up(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_hoist(e1) & n_boy(x2) & -(x2 = x1) & n_boy(x1) & n_boy(x1) & card_eq_1(x1))
exists p1 x1.(exists x2.((x1 = x2) & n_friend(x2)) & n_boy(x1) & card_eq_2(x1))