[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.


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>

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