A doctor is talking with a patient.
A nurse is talking to the doctor.
One cannot be a doctor and a nurse.
exists e1 x1 x2.(with(e1,x2) & n_patient(x2) & Actor(e1,x1) & v_talk(e1) & n_doctor(x1))
exists e1 x1 x2.(n_doctor(x2) & to(e1,x2) & Actor(e1,x1) & v_talk(e1) & n_nurse(x1))