[r-t] Shades of truth

[Don Morrison]

At the risk of nit-picking something that probably wasn't intended as
definitive:

On Wed, Sep 30, 2009 at 1:59 PM, Richard Smith <richard at ex-parrot.com> wrote:
> For example, we might start by saying that a true round block is one
> which:

Is "round block" really the term we want to use here? Is it not
normally used to describe a block that not only starts and ends with
rounds, but starts and ends at the same point of lead? So, for
example, Brian Price's 5,090 of Cambridge Major is not normally
considered a round block, right?

Since we're operating below the level of methods, shouldn't we pick
less loaded terminology?

On the other hand, the CC Decisions use the term "round block" without
defining it, and I guess with the same meaning you are. Hmm. Is round
block in current usage ambiguous?

>  [U] includes every row at most once; and
>  [R] starts and ends with the same row.
>
> (The initials are for 'uniqueness' and 'round block' respectively.)
...
>  [C] includes every possible row an equal non-zero number
>      of times.
...
>  [S] is completely divisible into one or more
>      non-overlapping blocks consecutive rows such that each
>      block individually satisfies [U], [R] and [C].
...
>  [B] is completely divisible into one or more
>      non-overlapping blocks consecutive rows such that each
>      block individually satisfies [U] and [C].

I suspect this is not the only formulation we could start from, and
arrive at versions equally sympathetic to existing practice, but
implying different relaxations going forward. That is, how we choose
to be descriptive may, in practice, subtly lead to prescriptions.

> And I can imagine someone might go further and, say, look for a 30,240 of
> Erin Triples where each row appears once in each position in a six, or a
> bobs-only 30,240 of Stedman Triples where each row appears once in each
> position of the appropriate parity.

In fact, there are some published MEBs of Stedman and Erin Doubles
that have similar properties.

> When this topic was discussed last year in the context of replacement
> decisions for peals, I think we made a fundamental mistake -- instead of
> trying to describe existing practice we tried to produce a single
> prescriptive definition.

Yes, I think you're right.

And I think the root of that error is simple. Those of us with a
somewhat liberal turn of thought generally start by tossing a
statement something like

  "We should prescribe the minimum that we need to call it 'ringing', for
   example what changes, rows and truth are, and just describe the rest."

Why do we include truth in that list? I'm certainly happy to have it
be a thing that varies with time and purpose. I suspect some others
may be more uncomfortable with that. As you've shown, however, if
*does* vary already, in two different ways

  - we have special case differences for different stages

  - it evolves over time

If folks can be persuaded to agree with you, I think it would be A
Good Thing. My own one reservation is the non-uniqueness of a
formulation, leading to implicit prescription. It's sort of analagous
to trying to define what a method is without constraining what folks
ring more than might be desired.



-- 
Don Morrison <dfm at ringing.org>
"It is hard to work without purposefulness.... It may be that
many people prefer involvement in bad purposes and wicked
creations to aimlessness and boredom in their occupation."
                    -- Jane Jacobs, _The Economy of Cities_