A man with work clothes on standing on the back of a truck.
The man is sitting on the back of a pickup truck eating his lunch.
Either the man is standing, or he is sitting and cannot be doing both at the same time.
exists x1 x2 x3 x4 x5 x6.(n_back(x5) & a_topic(x1) & with(x1,x2) & on(x2,x5) & of(x5,x6) & n_truck(x6) & on(x2,x4) & n_standing(x4) & n_clothes(x2) & of(x2,x3) & n_work(x3) & n_man(x1))
exists e2 e1 x1 x2 x3 x4 x5 x6.(n_lunch(x6) & of(x6,x2) & n_male(x2) & n_back(x2) & n_man(x1) & on(e1,x2) & of(x2,x3) & Theme(e2,x6) & Actor(e2,x5) & v_eat(e2) & (x3 = x5) & n_truck(x3) & of(x3,x4) & n_pickup(x4) & Actor(e1,x1) & v_sit(e1))