A pair of office workers are diligently performing their tasks on messy desks.
Office workers slacking off\
Slacking off implies the workers not performing any tasks at all, so it is the opposite of diligently performing their tasks.
exists e1 s1 s2 x1 x2 x3 x4 x5.(a_diligently(s2) & Manner(e1,s2) & on(e1,x5) & n_desk(x5) & a_messy(s1) & Theme(s1,x5) & Theme(e1,x4) & Actor(e1,x1) & v_perform(e1) & n_task(x4) & of(x4,x1) & n_thing(x1) & of(x1,x2) & n_worker(x2) & of(x2,x3) & n_office(x3) & n_pair(x1))
(x)