[r-t] Doubles 240s
mark at snowtiger.net
Fri Mar 20 22:24:51 UTC 2015
> Why on earth is any of this relevant? If the same row is rung twice, then
> the transformation from one to the other is the identity permutation.
But, as Martin Bright has pointed out, there is actually a difference
between "ringing the same row twice", and the identity change as we have
been discussing it.
In a performance of 60 on Thirds, there appear to be identity changes
between the called changes (which are all non-identity). However the
exact number of these is not material to the performance. Conversely, in
a multi-extent block of Minor with a row such as 123456 repeated in the
middle, the identity change is a material part of the performance -
there must be one and only one, if the length and truth of the
performance is to be correct.
You could argue that this is simply the difference between the two types
of performance, however it does show there is a clear difference in
treatment between two things which, if tagged with the word "identity
change", appear to be the same. And even in the Minor peal, the rounds
rows before and after are more similar to the identity changes in the
call-change peal than they are to the repeated 123456 in the middle of
To muddy things further, what if the MEB started with seven rows of
rounds? How would we distinguish the six "material" identity changes
required for this start from the indeterminate number of non-material
identity changes in the rounds beforehand?
I just don't like this very much!
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