[r-t] Definitions so far

[Don Morrison]

Thanks for all the thought and careful work that have obviously gone
into this. Here
are a few comments and questions.

On Sat, Jan 17, 2015 at 1:19 PM, Richard Smith <richard at ex-parrot.com> wrote:
> 3.  Bells are conventionally numbered with '1' denoting the
> highest pitched bell being used at the time, '2' denoting the
> second highest pitched bell, and so on.

Given the complex psychoacoustic phenomena around bells are we sure
that "highest pitched bell" is uniquely defined? Also, do we want to
worry about the possibility of towers with two bells pitched the same?

> 1.  A /row/ is a sequence of one or more blow.

I presume this is a minor typo and is intended to be "blows".

I believe it should explicitly state "a finite sequence".

> 4.  Rows are conventionally denoted by writing in sequence the
> number of the bells sounding each of its constituent blows.

Is this really true? Is it not the symbol representing that bell,
avoiding two digit numbers?

> 7.  When one or more bells sound in the same order the last
> blows of each row for an extended period, these bell are said
> to be /covering/.  When a covering bell is present, it is most
> commonly the tenor.

I'm having trouble parsing "sound in the same order the last blows of
each row". Is this a typo, or am I missing something?

I presume "an extended period" is deliberately vague? The difference
between a covering bell and the 4 in Cheeky Little Place Minimus
would seem to be an entirely social construct. Perhaps any definition
of covering needs to make the distinction between covering and currently
unusual methods explicit?

> 8.  A /working row/ is the representation of a row once any
> covering bells have been removed.  An /ordinary working row/
> is a working row which is also an ordinary row.  In casual
> speech, it is normal to refer to an ordinary working row as a
> "row", or even as a "change".  The latter use is discouraged.

It is not clear whether "latter" refers to "after ordinary working
row" or "after row". Perhaps it would be better to replace "the latter
use is discouraged" by something like "use of 'change' to refer to a
row is discouraged."?

>   (d) Any higher odd stages, 2n+1, is named using
>   Latin-derived name for an n-tuple names: 13 is /Sextuples/
>   from the Latin /sex/ meaning six, 15 is /Septuples/ from
>   /septem/ meaning seven, etc.

Minor typo(s) here, should be "any higher odd stage" or "are named",
etc.


On Tue, Jan 20, 2015 at 3:48 AM, Richard Smith <richard at ex-parrot.com> wrote:
> A comment Iain made to me off-list over the weekend has persuaded me that I
> should change some of my definitions re changes.

>   (c)  An /ordinary change/ is any change that combines the
>   effect of one or more plain changes, each of which affects
>   different bells.  The null change is excluded from this
>   definition by convention.

The last sentence is redundant. I presume this is intentional.

I fear "each of which affects different bells" is ambigous.
I can imagine someone reading this thinking "1-2" and "2-3" are
"different bells" since they are different pairs of bells.

It's a little surprising that changes are defined in terms of
positions, but kinds of changes are defined in terms of bells.
I don't think it causes any trouble, but does set me to
scratching my head.

>   (d)  A /jump change/ is any progression between ordinary
>   rows that is not an ordinary change, nor the null change.

It might better to phrase this as "any progression between ordinary
rows that cannot be described by an ordinary change, nor the null
change". While no ringer would do this, I could imagine a naive
non-ringer coming to these definitions, and starting to think in terms
of swapping around pairs of bells. And coming up with the "change"
that consists of apply swaps of positions 1-2, 2-3, 4-5, then 2-3
again, and concluding that results in a jump change. This potential
issue may afflict some of the earlier kinds of changes.

>   (b) The /cross change/ is the ordinary change in which every
>   bell swaps places with an adjacent bell.

Shouldn't this be "a cross change"? I don't think "the cross change"
is unique. Isn't there a different one for each even stage?

> 5.  A /stage change/ is a change that progresses from a row of
> one stage to a row of a different stage.
>
> 6.  A /cover change/ is change other than a stage change which
> either alters the choice of covering bell or bells, or alters
> the order in which they strike.

It may be a failure of my imagination, but I'm having trouble
reconciling these non-working changes with the definition of change. A
"transposition" doesn't seem to have any room for bells appearing and
disappearing, does it?

> 8.  Ordinary working changes (and the null change) are
> conventionally denoted by writing in order the places made.
> For example, in Minimus the single change that swaps the bells
> in seconds and thirds place is denoted '14', as places are
> made in first and fourths place.  Bell symbols are used for
> places above ninths place.  The cross change is variously
> denoted 'X', 'x' or '-'.  This representation of a change is
> called its /place notation/.

This representation is the heart of place notation, but place notation
requires a little bit more, doesn't it? A convention for
disambiguating adjacent non-cross changes, and the convention for
(optionally) eliding some unneeded places.

On Tue, Jan 20, 2015 at 7:54 AM, Richard Smith <richard at ex-parrot.com> wrote:
> I think I'm now happy with the next section of my definitions.

> 1.  A /block/ is a sequence of rows where the progression
> between rows is defined by changes.  A /sub-block/ of some
> block is a sequence of contiguous rows from that block.  It
> too is a block.

Must a block be finite? Must it be of non-zero length? Must
a sub-block be of non-zero length?

> 2.  When a block is a sub-block of some larger block and does
> not include the last row of the larger block, it additionally
> has a /block-end change/.

While I suppose one could argue it is really 1+2 that defines
sub-block, it does seem kind of contradictory. Should
(1) say something like "A sub-block of some block is a
sequence of contiguous rows, possibly plus a change, plus
a citation of its parent block"?

All in all this whole sub-block thing seems confusing. It is a more
complex entity than just a sub-sequence, but how much more complex
depends upon its parent block. Perhaps there needs to be another
entity defined which is a block plus a change, and that then is, under
appropriate circumstances, a sub-entity of a block? I dunno, maybe I'm
completely missing something, but it is making my brain itch.

> A block without a block-end change is
> called a /terminal block/, and a block with one, a
> /non-terminal block/.

The same block can be a terminal block and a non-terminal block,
since its terminality depends upon the identity of a parent block.
Or am I missing something?

> Usually the opening block and closing block constists of just
> rounds, and referred to as the /opening rounds/ and /closing
> rounds/, respectively.

Needs the verb "are", I believe.





-- 
Don Morrison <dfm at ringing.org>
"Inconceivable!" "You keep using that word!...I don't think it means
what you think it does."         -- William Goldman, _The Princess Bride_