Well, what I can say is that the position that was adopted by the UK Government in the Miller case—the article 50 case—was very clear: that it was not revocable. Of course, the ultimate body that would determine the legality of that would be the European Court of Justice, but as a matter of general principles and agreement with regard to the European Union, any agreement that has the consent of all the members of the European Union can achieve almost any position that is wanted to achieve.