Two laborers are working on a roof with a bright blue sky in the background.
Two laborers are fixing a roof.
People working on a roof are not necessarily fixing it.
exists e1 s1 s2 x1 x2 x3 x4.(n_background(x4) & on(e1,x2) & with(x2,x3) & in(x3,x4) & n_sky(x3) & a_blue(s2) & Theme(s2,x3) & a_bright(s1) & Theme(s1,x3) & n_roof(x2) & Actor(e1,x1) & v_work(e1) & n_laborer(x1) & card_eq_2(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_fix(e1) & n_roof(x2) & n_laborer(x1) & card_eq_2(x1))