A man in a suit is observing an item through a window.
Nobody is observing
Nobody refers to no one. A man is atleast one person.
exists e1 x1 x2 x3 x4.(through(e1,x4) & n_window(x4) & Theme(e1,x3) & Actor(e1,x1) & v_observe(e1) & n_item(x3) & in(x1,x2) & n_suit(x2) & n_man(x1))
-exists e1 x1.(Actor(e1,x1) & v_observe(e1) & n_person(x1))