One mechanic is sitting on the roof of a school bus with an open door, while the other is standing inside the bus.
The mechanics are working on the school bus.
We have no idea if they are working on the bus, they could be doing a number of things to the bus.
exists e1 p1 s1 x1 x2 x3 x4 x5 x6.(n_other(x6) & n_roof(x2) & exists e2.(inside(e2,x3) & Actor(e2,x6) & v_stand(e2)) & n_bus(x3) & n_bus(x3) & while(e1,p1) & with(e1,x5) & n_door(x5) & a_open(s1) & Theme(s1,x5) & on(e1,x2) & of(x2,x3) & of(x3,x4) & n_school(x4) & Actor(e1,x1) & v_sit(e1) & n_mechanic(x1) & card_eq_1(x1))
exists e1 x1 x2 x3.(n_bus(x2) & of(x2,x3) & n_school(x3) & n_mechanic(x1) & on(e1,x2) & Actor(e1,x1) & v_work(e1))