[r-t] Shipway Minor

[Alexander Holroyd]

> On 16 Jun 2014, at 22:49, Alexander Holroyd <holroyd at math.ubc.ca> wrote:
>> Well, don't forget that the "division" (or lead) of shipway consists of 
>> two eights, so the Stedman Triples type calls already occur in two 
>> places in the lead (as they do in Stedman).  So I don't know what the 
>> "obvious calls" are, and the extremes are actually division-end calls 
>> (if you start at a symmetry point).  So my extent actually has 5 
>> different types of call, although that doesn't bother me…
>
> I make no apology for considering the "division end" to not be at the 
> same point as we (conventionally) start the method. I also consider both 
> quick and slow eights to be separate divisions (and the method to be 
> made of strictly alternating between the two), so standard Stedman bobs 
> are in my view all at division ends.

Well, under this logic, I suppose every call in every method is at a 
division end.  One can simply define the lead to be composed of as many 
divisions as desired.  :-)  Hence the need for human judgement in 
determining "reasonableness".  I think we basically agree on what this 
should mean - I just prefer to do it without the need for the intermediate 
concept of a division (which itself requires judgement if it is to be 
useful).  In particular I completely agree that Shipway with only bobs and 
singles would be better (but I be equally happy with bobs and extremes).

>> I suspect a MEB is possible with only one type of call, even _any_ call 
>> that doesn't obviously fail for some reason.  In fact there might even 
>> be a general theorem to that effect.
>
> Sketch of proof if the call you want to use can access every possible 
> course (usually true for a single):

Yup, sounds right!