a shirtless boy opening something.
A boy who isn't wearing a shirt opens something.
Shirtless is the same as isn't wearing a shirt.
exists e1 s1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_open(e1) & n_thing(x3) & (x1 = x2) & n_boy(x1) & a_shirtless(s1) & Theme(s1,x1))
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_open(e1) & n_thing(x3) & -exists e2 x4.(Theme(e2,x4) & Actor(e2,x2) & v_wear(e2) & n_shirt(x4)) & (x1 = x2) & n_boy(x1))