A man in a sweater is looking at dirty stairs.
The man is a janitor.
not every man is a janitor.
exists e1 s1 x1 x2 x3.(at(e1,x3) & n_stair(x3) & a_dirty(s1) & Theme(s1,x3) & Actor(e1,x1) & v_look(e1) & in(x1,x2) & n_sweater(x2) & n_man(x1))
exists p1 x1.(n_man(x1) & exists x2.((x1 = x2) & n_janitor(x2)))