[r-t] Complexity of extents

[Philip Saddleton]

See RW 1999 p728. The extent consisted of two 10-part blocks (part end 
5123476), with the rows of one being inverted and rung backwards to give 
the other.

PABS

On 28/06/2013 14:24, Alexander Holroyd wrote:
> I vaguely remember that PABS had an extent of the principle 
> 7.1.7.1.7.1.345 with calls 3 and 5 that exploited an unusual kind of 
> symmetry.  (Perhaps he would care to remind us).
> A
>
> On Mon, 24 Jun 2013, Richard Smith wrote:
>
>> Andrew Johnson wrote:
>>
>>>> From: Richard Smith <richard at ex-parrot.com>
>>>> But when I try to get an extent with rotational symmetry, it
>>>> feels like I'm fighting against the symmetry rather than
>>>> utilising it.
>>>>
>>> It's not an extent, but for rotational symmetry were
>>> you thinking of compositions such as Ander's 5024 Bristol S.
>>> Major?
>>
>> Not really.  I think the difference between an extent an 
>> eighth-extent (a peal of major) is significant.  I was thinking more 
>> of extents on four, five or six.  I can't say I've ever tried to 
>> produce a rotationally symmetric peal of major.
>>
>> Naïvely you wouldn't necessarily expect a rotationally symmetric 
>> extent to be any harder to produce than a palindromic one.  Both 
>> symmetries constrain half of the rows.  But, at least in my 
>> experience, a rotationally symmetric extent (that's not also 
>> palindromic) feels a much tougher proposition than a palindromic one.
>>
>> RAS
>> _______________________________________________
>> ringing-theory mailing list
>> ringing-theory at bellringers.net
>> http://bellringers.net/mailman/listinfo/ringing-theory_bellringers.net
>>
>>
> _______________________________________________
> ringing-theory mailing list
> ringing-theory at bellringers.net
> http://bellringers.net/mailman/listinfo/ringing-theory_bellringers.net
>