A man wearing a gray shirt is tuning his guitar.
A man wearing a hat is about to perform.
A man wearing a gray shirt is tuning his guitar does not indicate he is wearing a hat
exists e1 e2 s1 x1 x2 x3 x4.(Theme(e2,x4) & Actor(e2,x1) & v_tune(e2) & n_guitar(x4) & of(x4,x1) & n_male(x1) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_shirt(x3) & a_gray(s1) & Theme(s1,x3) & (x1 = x2) & n_man(x1))
exists e1 p1 s1 x1 x2 x3.(Topic(s1,p1) & Actor(s1,x1) & a_about(s1) & exists e2.(Actor(e2,x1) & v_perform(e2)) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_hat(x3) & (x1 = x2) & n_man(x1))