A shirtless man is working on a roof.
The man is working on the front yard.
Your front yard is on the ground, not on the roof.
exists e1 s1 x1 x2.(on(e1,x2) & n_roof(x2) & Actor(e1,x1) & v_work(e1) & n_man(x1) & a_shirtless(s1) & Theme(s1,x1))
exists e1 x1 x2 x3.(n_yard(x2) & of(x2,x3) & n_front(x3) & n_man(x1) & on(e1,x2) & Actor(e1,x1) & v_work(e1))