A guy in a white shirt skateboarding on a ramp.
The guy is practicing for a skateboard competition.
A guy in a white shirt skateboarding on a ramp is not necessarily practicing for a skateboard competition.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & in(x1,x2) & on(e1,x4) & n_ramp(x4) & Actor(e1,x3) & v_skateboard(e1) & (x2 = x3) & n_shirt(x2) & a_white(s1) & Theme(s1,x2) & n_guy(x1))
exists e1 s1 x1 x2.(n_guy(x1) & for(e1,x2) & n_competition(x2) & a_skateboard(s1) & Theme(s1,x2) & Actor(e1,x1) & v_practice(e1))