[r-t] Notating jump changes (was Blue line (/grid) generators / Jump Changes)

[Don Morrison]

On Mon, Mar 23, 2015 at 6:46 AM, Alexander Holroyd <holroyd at math.ubc.ca> wrote:
> On notation, since jump methods tend to have relatively few and small jumps,
> I like using (xy) for a jump from place x to place y (where |x-y|>=2), and
> as usual z for zths place made, so e.g.
>
> (13)4 denotes
> 23146587
>
> (13)(31)8 or (13)(31) denotes
> 32154768
>
> (13)(42) denotes
> 24136587
>
> I think it's true (but perhaps not completely obvious) that there is always
> at most one way to fill in the remainder of such a change with non-jumping
> bells.

Yes and no.

Consider your (13)(31) example. But expand it to (15)(51). Is that now
52431768 or 53241768? If we say "oh, you only have to specify the
stuff in between if it's not uniquely determined" that not only gets a
little fuzzy, it is, I think, contrary to usual practice with normal
place notation where I don't think most folks would ever write 35
instead 345 or 3458.

Or should (13)(31) instead be (13)2(31)?

And is (13)2(31) really any clearer than 32154768? It's no shorter for
major, a little longer for doubles, and significantly shorter for
sixteen. I guess it does have one big benefit, though, in that it
applies without change to all stages minimus and above.



-- 
Don Morrison <dfm at ringing.org>
"Washington was immobilized by snow on Friday. This is highly
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              -- Gail Collins, _The New York Times_, 5 February 2010