[r-t] proving a touch

[Graham John]

Ian wrote:

> I think, for cambridge though, that it does contain all 720
> rows, as well as no rows appearing more than twice.  
> So I don't know what the footnote is supposed to mean.
> What other criteria could there be that it fails for Cambridge?

You are quite right Ian. It is true to Cambridge, but not Beverley, so it
seems to have been published the wrong way round.

I would define true as follows:

True: A round block is considered true if all its rows are distinct, or if
longer than one extent, are distinct if the rows from any complete extents
are excluded.

Graham