Human rights — Alleged violation of the obligation under Article 7 of the European Convention on Human Rights, 1950 — Whether appellant convicted of co-perpetration of a conspiracy to commit mafia-related offences knowing their conduct at the time when it took place — Scope of the judgment of the European Court of Human Rights in Contrada v. Italy — Whether appellant benefitting from Article 46 of the European Convention concerning a State’s obligation to comply with judgments of the European Court of Human Rights — Whether judgment in Contrada v. Italy being a pilot judgment — Whether judgment in Contrada v. Italy finding structural defect in Italian legal system capable of violating obligations under Article 7 of the European Convention in regard to plurality of individuals — Whether co-perpetration of a conspiracy to commit mafia-related offences being a judicially created offence — Relationship between primary legislation and judicial decisions — Precedent — Difference between binding and persuasive precedent — Whether jurisprudential debate as to scope of co-perpetration of a conspiracy to commit mafia-related offences being settled at the time of appellant’s conduct — Whether appellant being able to foresee that conduct could generate criminal responsibility and punishment — Whether principle of legality being breached — The law of Italy