The man without a shirt is sitting on a rock by a tree.
The shirtless man sunbathed on the rock,
There is no mention what time, or what the weather conditions are, the man has not necessarily sunbathed on the rock.
exists e1 x1 x2 x3.(n_man(x1) & by(e1,x3) & n_tree(x3) & on(e1,x2) & n_rock(x2) & Actor(e1,x1) & v_sit(e1) & -exists x4.(with(x1,x4) & n_shirt(x4)))
exists e1 s1 x1 x2 x3.(n_rock(x3) & n_man(x1) & a_shirtless(s1) & Theme(s1,x1) & a_topic(x1) & on(e1,x3) & Theme(e1,x2) & v_sunbathe(e1) & (x1 = x2))