A man in a white shirt messing with a ladder.
A person preparing a ladder to climb his roof.
A man may be messing with a ladder but it may not be necessarily  to climb his roof; it can be for any other purpose.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & in(x1,x2) & with(e1,x4) & n_ladder(x4) & Actor(e1,x3) & v_mess(e1) & (x2 = x3) & n_shirt(x2) & a_white(s1) & Theme(s1,x2) & n_man(x1))
exists e1 p1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_prepare(e1) & Topic(x3,p1) & exists e2.(Theme(e2,x4) & Actor(e2,x3) & v_climb(e2)) & n_roof(x4) & of(x4,x1) & n_male(x1) & n_ladder(x3) & (x1 = x2) & n_person(x1))