The bike is secured to a metal post.
John is riding the bike around the yard.
If the bike is secured to a metal post a person cannot be riding the bike.
exists e1 x1 x2 x3.(n_bike(x1) & to(e1,x2) & n_post(x2) & of(x2,x3) & n_metal(x3) & Theme(e1,x1) & v_secure(e1))
exists e1 x1 x2 x3.(n_yard(x3) & n_bike(x2) & ne_per_john(x1) & around(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1))