The hikers take a tandem leap while crossing the bridge.
The hikers are crossing the bridge.
While crossing the bridge means one is crossing the bridge.
exists e1 e2 x1 x2 x3 x4.(n_bridge(x4) & n_hiker(x1) & while(e1,e2) & Theme(e2,x4) & Actor(e2,x1) & v_cross(e2) & Theme(e1,x2) & Actor(e1,x1) & v_take(e1) & n_leap(x2) & of(x2,x3) & n_tandem(x3))
exists e1 x1 x2.(n_bridge(x2) & n_hiker(x1) & Theme(e1,x2) & Actor(e1,x1) & v_cross(e1))