[r-t] Decisions / Algorithms for generating the extent
Philip Saddleton
pabs at cantab.net
Wed Jun 21 18:42:42 UTC 2006
Possibly, but better to use
23456...n1 and 13456...n2
think of the plain course as applying the first n times, and a single
swapping two bells.
Philip
Alexander Holroyd said on 21/06/2006 18:19:
> I seem to remember hearing that on any number, the extent can be produced
> by 213456...n and the jump change 23456...n1 (Obviously the group is
> generated by these two, but I am talking about an actual extent).
>
> Ander
>
> On Wed, 21 Jun 2006, Don Morrison wrote:
>
>> On 6/21/06, Richard Smith <richard at ex-parrot.com> wrote:
>>
>>> The algorithm for generating an extent on n by applying
>>> plain changes on n-1 to the coursing order of plain hunt on
>>> n has the elegant property that only three different changes
>>> are needed. By contrast, plain changes needs n-1 different
>>> changes, as does the Original Singles, Bob Minimus, Old
>>> Doubles, ... sequence.
>> Am I correct in believing that for more than three bells, three
>> different changes is the minimum that can ever be used to generate an
>> extent?
>>
>> That's assuming ordinary changes, not jump changes. Can it be reduced
>> to two with jump changes?
>>
>>
>> --
>> Don Morrison <dfm at mv.com>
More information about the ringing-theory
mailing list