[r-t] proving a touch

[Graham John]

I wrote:

> 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.

In addition to being true, I like quarters of Minor that do not contain
Rounds (internally), such as the one below.

1296 Cambridge S Minor
By GACJ

  123456 3
s 132564 1
s 162453 1
- 125346 3
- 125463 2
s 143256 3
s 134562 1
s 164253 3
- 164532 1
s 134256 

Repeat twice.

Graham