[r-t] Extension question
robin at robinw.org.uk
Mon Nov 6 17:17:54 UTC 2017
Following from my last.
To keep it 'simple'.
Work I did years previously to the Anglia problem showed the following.
In the 1961/75 collection of Minor methods, there were two sorts of
Alliance methods - ordinary & special. Ordinary had dodging only in 5-6
and Special had plain sections only in 1-2. I showed from these that
Alliance methods can only extend from the 'internal sections' so
Ordinary Alliance extended could *only* have dodging in the last place
(at all stages) and Special could only have a plain section 1-2.
The reason for this is 'work'. Taking extension above the treble as
example, if I choose to extend an Special Alliance method by AB-above,
then I have ABA'B' above in the parent which is plain. However, the work
below the treble in the second section is dodging since all extension
paths below must include the C section. (By symmetry, any alliance
cannot extend by the last sections - FG for Minor).
In summary, an Ordinary Alliance minor method can be denoted as PPT and
it's extension must be PPPT - in an obvious notation. (We omit the
treble passing between 1-2 and 3-4 from the notation). A Special
Alliance is PTT and the extension must be PTTT, etc.
In as few words as possible, the work above and below the treble must be
of the same 'type'.
Don asks: 'If a hunt path like this does expand, as your answer seems to
imply, does that mean a major method with the treble dodging in 1-2, 3-4
and 7-8, when extended to royal, must have the treble dodging in 1-2,
3-4, 5-6 and 9-10?' Answer - Not exclusively!
(b.t.w., I remember discussing this with RAS when he was devising his
extension program about 15 years ago.)
To Semi.... We are looking at the work when the treble is in 7-8-9-0.
In Major, the treble work is 5-6-5-6-7-8-7, in Royal
5-6-5-6-7-8-7-8-9-0-9. It seems intuitive, therefore, that we have a
perfectly good 1DE extension. We have preserved the 'type' of the
section(s) when the treble is doing its backwork.
Don's real question seems to be related to the Formula BUT the formula
quoted in (G)C2 is but one example of many. There are other formulae for
parental methods on 6 bells, on 7, etc. Here, we have a method which
does not include position 'I' - position H is the last and we can
construct a whole set of extensions based on this.
I have concluded that Don's Royal method is a correct extension of the
major. I base this on the Minor examples above. (Note the definition of
section H is 'treble in 7-8'. It is section I which says 'treble lying'
- which it doesn't here.) We have seen that the last section's type has
to appear once and once only once in the extension and it does so.
b.t.w., this is not a 'Little' method by definition.
Whether it's the only extension is another matter!
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