A boy with a blue shirt is standing on the railing of a flight of stairs.
a boy is showing off on the railing
A boy standing does not imply showing off.
exists e1 s1 x1 x2 x3 x4 x5.(n_railing(x3) & on(e1,x3) & of(x3,x4) & of(x4,x5) & n_stair(x5) & n_flight(x4) & Actor(e1,x1) & v_stand(e1) & with(x1,x2) & n_shirt(x2) & a_blue(s1) & Theme(s1,x2) & n_boy(x1))
exists e1 s1 x1 x2.(n_railing(x2) & a_off(s1) & Manner(e1,s1) & on(e1,x2) & Actor(e1,x1) & v_show(e1) & n_boy(x1))