A shirtless boy punches snow.
a boy punches snow
The two statements are saying the same thing: the boy punches snow
exists s1 x1 x2 x3.(a_topic(x1) & n_snow(x1) & of(x1,x3) & n_punch(x3) & of(x1,x2) & n_boy(x2) & a_shirtless(s1) & Theme(s1,x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_punch(e1) & n_snow(x2) & n_boy(x1))