Re: Tetrits and "stickiness"
> From: "Nate Hayes" <nh@xxxxxxxxxxxxxxxxx>
> To: "P1788" <stds-1788@xxxxxxxxxxxxxxxxx>, "Michel Hack" <hack@xxxxxxxxxxxxxx>
> Subject: Re: Tetrits and "stickiness"
> Date: Thu, 15 Apr 2010 16:12:07 -0500
>
> Michel Hack wrote:
> >> . . .
>
> >
> > If the sticky bits represent the same information as the detailed bits
> > for a single operation, then yes, it would be sufficient to implement
> > the sticky bits, and have the program clear the sticky bits before
> > every operation. I was under the impression however that the detailed
> > bits proposed by Dan Zuras carried more information than can be
> > handled as a sticky bit.
>
> Ok. That makes sense.
>
> My understanding is they do represent the same information, i.e., that an
> "octrit" is comprised of two "tetrits," each tetrit representing the same
> information except one is sticky and the other is not. So I was liking the
> idea of "tetrit" but scratching my head wondering why we need "octrits".
>
> Nate
>
>
> >
> > . . .
> >
No, actually. What I had in mind was collecting only the
exceptional or notable information in a third bit. Thus,
'octit' for 8 states. (Or is it octigit? It can't be
octrit as it is a contraction of 'octal digit'. It could
be octagit. :-)
But this presumes that the decoration is named for some
unexceptional property. 'domain' for 'in the domain'.
'continuous' like most function we use in intervals.
Or 'bounded' as in 'still finite'. Then it presumes that
the information we wish to retain as sticky is the other
or exceptional property. 'domainFalse' or 'domainOut'
for 'we strayed from the proper definition of this function'.
'continuousFalse' or even 'discontinuous' for the obvious
if hard to define property. And, 'boundedFalse' or even
'unbounded' for either overflow or an actual singularity.
As one retains no diagnostic value by 'sticking' the
states we expect, it should be sufficient to retain only
those things are are unusual, exceptional, or otherwise
worthy of note to the diagnostician.
This is why Nate's approach may have merit. If we can
fit everything we need to know about an operation into
4 states then 2 bits suffice. But if we need 5 states
we're hosed without another bit.
Simplicity may also be an argument for using another
bit or even two.
But let me suggest that we lock the meaning of tetrits
first.
Whether we decorate a result with the tetrits or
decorate it with some other state designed to retain
the sticky information need not concern us yet.
Let's agree on whether the tetrits contain the
information we want to see on THIS operation for the
moment.
After we agree on that, we will have a better handle on
what needs to be kept & what can be discarded.
Just a suggestion...
Dan