dfm at ringing.org
Mon Jun 9 00:52:27 UTC 2014
On Sat, Jun 7, 2014 at 12:45 PM, Graham John <graham at changeringing.co.uk> wrote:
> I wouldn't alter the definition of a change, but I would
> introduce a definition for a null change. As a null change is then not a
> change, you just do not count it as a change.
I'm sorry, but I think this is an exceedingly ill-advised suggestion.
What we ringers ring are rows, not changes. What you are proposing
says sometimes we pretend we haven't rung some of the rows we have
rung. In particular you are saying that whether or not we say we have
rung a row is not just a property of us ringing the bells in that
order, but of what the preceding row we rang was.
Consider the following two multi-extent blocks.
a) We ring two consecutive extents of Plain Bob Doubles, using the
standard calling with the 2 unaffected. I think we'll all agree we've
rung a perfectly acceptable touch of length 240. Each possible row
appears twice, each row appearing either twice at hand or twice at back.
b) Now we ring the same extent of Bob Doubles, and at the very end add
a 12345 single Home, and repeat. The touch we've rung again contains
every possible row twice, though now with the nice property that each
row appears once at hand and once at back: it might even be argued by
those of certain tastes and persuasions that this makes it a "better",
more "worthy" touch, I suppose. But according to your proposal it's
not a 240, it's a 238.
But (a) and (b) contain exactly the same rows. They take exactly the
same length of time to ring. How can they be of different lengths? How
can one be true, in the sense of containing every row exactly twice,
and the other not be?
Don Morrison <dfm at ringing.org>
"History...is the noblest form of blackmail. Every leader of
consequence knows that the eyes of the future will eventually fasten
on him, and that he will pay with his reputation for even the
best-hidden crimes." --Mark Edmundson, _Why Read?_
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