A man is steaming milk at an espresso machine.
The man is at work.
Steaming milk does not necessarily mean at work.
exists e1 x1 x2 x3 x4.(at(e1,x3) & n_machine(x3) & of(x3,x4) & n_espresso(x4) & Theme(e1,x2) & Actor(e1,x1) & v_steam(e1) & n_milk(x2) & n_man(x1))
exists p1 x1.(n_man(x1) & exists x2.(at(x1,x2) & n_work(x2)))