A surgeon calibrates his machinery.
The surgeon doesn't work on machinery.
If a surgeon calibrates his machinery then he does work on his machinery.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_calibrate(e1) & n_machinery(x2) & of(x2,x1) & n_male(x1) & n_surgeon(x1))
exists x1.(n_surgeon(x1) & -exists e1 x2.(on(e1,x2) & n_machinery(x2) & Actor(e1,x1) & v_work(e1)))