1. Member States may provide that periods of theoretical instruction in the fields referred to in Article 8 shall count towards the periods of professional activity referred to in Article 11, provided that such instruction is attested by an examination recognised by the State. Such instruction shall not last less than one year, nor may it reduce the period of professional activity by more than four years.
2. The period of professional activity and practical training shall not be shorter than the course of theoretical instruction together with the practical training required in Article 10.