[r-t] Definitions so far

[Don Morrison]

Thanks for the prompt reply. Here are some easy re-replies; some
of the other points I'm going to have to digest more carefully
before replying to.

On Tue, Jan 20, 2015 at 4:00 PM, Richard Smith <richard at ex-parrot.com> wrote:
> Personally I'm not too concerned about this.  Is anyone else?

If you, who has ready opportunities to ring at St Edward King and
Martyr, are not worried about psychoacoustics, I'm sure not going to.

>>> 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.

Just noticed something I missed the first time around: would it not
be better to say "bell symbols" all the way around, rather than
thinking numbers for <= 9 and symbols for > 9?

> The place notation of a block needs separators, but here I'm defining the
> place notation of a change.

Oops, sorry, missed that nicety!

> Let me have a go at reformulating these two definitions.
>
> 1.  A /block/ is a finite sequence of one or more rows, listed
> in the order they are to rung, together optionally with a
> change referred to as its /block-end change/.

I think "to be rung"?

> 2.  A block may be divided into /sub-blocks/ whose rows are a
> sequence of contiguous rows from the parent block.

This seems to be saying we partition a block into sub-blocks, rather
than simply extracting a sub-block out of a block. It's not clear
that there's anything wrong with that, it's just a little surprising.

I think I might phrase it something more like "a sub-block of a block,
the parent block, is itself a block whose rows are a sequence of
contiguous rows from the parent block". Either that, or explicitly
state that the sub-block, too, must contain one or more rows. I
realize that immediately after the preceding sentence you do say "a
sub-block is a block" but that sounds more like it's being stated as a
consequence of the definition, rather than as another clause of the
definition.

> A
> sub-block is a block.  If the sub-block's rows do not include
> the last row of the parent block, then its block-end change is
> the change describing the progression from the last row of the
> sub-block to the first row not included in the block.
> Otherwise the sub-block's block-end change is the block-end
> change of the parent block, if it has one.
>
> 3.  A block without a block-end change is called a /terminal
> block/, and a block with one, a /non-terminal block/.

I think I'd exchange 2 and 3: that is, define all of block, terminal
block and non-terminal block before starting to worry about
sub-blocks.




-- 
Don Morrison <dfm at ringing.org>
"After all these years I have observed that beauty, like happiness,
is frequent. A day does not pass when we are not, for an instant,
in paradise."
        -- Jorge Luis Borges, _Los Conjurados_, tr Willis Barnstone