It was U.S. President Harry Truman who is alleged to have said, "Bring me a one-handed economist." He was just about fed up with endless economic and political analysts saying "on the one hand, but on the other hand," etc.
Japanese visitors to Britain enquiring about Brexit must have the same feelings of exasperation, as every question about what happens next over Brexit is met with streams of "ifs" and "buts" and "maybes," or just honest "don't knows."
So here for a change is a firm description of what will happen — no ifs, no buts.