Two boys are riding a zipline between trees.
Two boys are between trees.
A zipline is between trees so if the boys are riding a zipline then they are between trees.
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & between(x2,x3) & n_tree(x3) & n_zipline(x2) & n_boy(x1) & card_eq_2(x1))
exists p1 x1.(exists x2.(between(x1,x2) & n_tree(x2)) & n_boy(x1) & card_eq_2(x1))