Two men, both wearing bright yellow vests and jeans, are working on a roof.
two men are fixing their sisters roof
It doesn't state in sentence one that they are fixing their sisters roof. It is not implied in the first sentence alone.
exists e1 e2 s1 s2 x1 x2 x3 x4 x5 x6.(n_jeans(x5) & n_vest(x4) & subset_of(x5,x3) & subset_of(x4,x3) & a_yellow(s2) & Theme(s2,x3) & a_bright(s1) & Theme(s1,x3) & Actor(e1,x3) & v_wear(e1) & on(e2,x6) & n_roof(x6) & Actor(e2,x1) & v_work(e2) & subset_of(x3,x1) & subset_of(x2,x1) & n_man(x2) & card_eq_2(x2))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_fix(e1) & n_roof(x2) & of(x2,x3) & n_sister(x3) & of(x2,x1) & n_thing(x1) & n_man(x1) & card_eq_2(x1))