My Lords, I thank the noble Lord for trying to cast light into my ignorance, but it is getting worse; the fog is getting thicker. Does the no-detriment principle have a reciprocal? If not, why not? Should there not be a reciprocal? Let us suppose there was a tax change that widened the tax base. Would that be no detriment just to the Scots, or no detriment to the UK? Before the Minister responds, perhaps I may make a second point. I see two little gleams of light from the lighthouse in the fog. One was the suggestion made by the noble Lord, Lord Browne, that it might be good if one could set out on paper how this is to work. I should have got there long ago, but I had not realised it. That is central to the issue of accountability, but I had not quite got it. I turn now to the noble Lord, Lord Stewartby, for the second light. Since it is so central to the issue of accountability, should it not be on the face of the Bill?