A group of bike riders are riding on the street.
There are bikers outdoors.
Group of bike riders are bikers, and street implies outdoors.
exists e1 x1 x2 x3 x4.(n_street(x4) & on(e1,x4) & Actor(e1,x1) & v_ride(e1) & of(x1,x2) & n_rider(x2) & of(x2,x3) & n_bike(x3) & n_group(x1))
exists p1 x1 x2 x3.((x1 = x2) & n_outdoors(x2) & of(x2,x3) & n_biker(x3))