robin at robinw.org.uk
Sat Apr 8 09:09:21 UTC 2017
A reply to Roddy.
"I do not believe this to be within the remit of the methods committee."
Someone has to do it!
As regards Extension, Roddy seems to be advocating subjectiveness here.
It is dangerous to go down the route of saying just because a method I
wanted to extend according to a set of objective rules doesn't, we
should throw out the baby, not with the bath-water, but with the
wee-wee. It is arguing from the particular to the general.
I did ask Roddy to publish the extensions he came up with, but the
problem remains that if you say 'I think this is an extension' someone
will inevitably take issue with your assertion. Think again of Ipswich
S8. I ask the question 'where did the 1-2 dodging come from?' (I don't
expect/want an answer.) In this area, you cannot get away with saying 'I
think..' - it needs to be proved - chapter & verse if you like.
'Watertight' is the current phrase.
Given that change-ringing is a branch of algebra, we should all be
comfortable with the fact that, in any given axiom-set, there will be
methods which only exist at one, or at most two, stages - such as London S6.
Here is a perfectly good formulaic extension of Beverley at all stages:
&-3-4-2-3.4-34.5.4-34.5,2; but it is irregular at all stages<>0mod6.
However, it doesn't look much like Beverley below! (It is the 'York'
extension above.) This is, of course, the intuitive extension as it
consists of the last section being repeated ad infinitem. The Major &
Royal could have been called something like Beverley No.1 or Bevearlea
or Beferlic leaving the Maximus to be called Beverley, but there we are.
As has been remarked before, types of 'irregular' lead-ends are not
distinguished in the Decisions - tho' I did some preparatory work on
this a couple of years ago in communication with Tim Barnes. Whether
lead-end type is important here is another matter - tho' I remember
someone remarking that regular should remain so in their opinion.
I say again, it would be of help if Roddy could publish his versions.
More information about the ringing-theory