Re: Tetrits, bool_set and "discontinuous" bit
> From: "Nate Hayes" <nh@xxxxxxxxxxxxxxxxx>
> To: "P-1788" <stds-1788@xxxxxxxxxxxxxxxxx>
> Subject: Tetrits, bool_set and "discontinuous" bit
> Date: Thu, 23 Sep 2010 07:46:07 -0500
>
> P1788,
>
> An argument was recently made to me, something to the extent:
>
> "Why not just change the tetrit priority ranking value R to 3-R and then
> take the supremum of two tetrit values? The domain tetrit will then be
> consistent with the discontinuous bit (which uses disjunction)."
>
> . . .
>
> So if P1788 wishes the following to be true:
>
> -- The propagation of all decorations shall be handled uniformly, i.e.,
> with conjunction/infimum or disjunction/supremum (but not some wild
> combination of both)
>
> -- The IEEE 1788 definition of a tetrit shall be compatible with the
> proposed C++ bool_set standard
>
> Then the only choice is to accept the current definition of a tetrit, i.e.,
> Motion 18, and standardize "defined and continuous" as opposed to
> "discontinuous."
>
> Sincerely,
>
> Nate
Nate,
I think it would serve us well if we specified both the nature
of decorations & their propagation at the level of truth values
& conjunction or disjunction of those truth values rather than
as bits.
Then names, what is kept during propagation, & the methods of
propagation all become implementation details. Some people
can store the bad thing as zero & propagate via AND. Some
can store them as one & propagate via OR. They can do it
uniformly if they're smart. Or wildly if they're not. We
don't need to know or care. Its all a matter of how some
software interface accesses those bits & turns them back into
truth values when we look at them.
Alas, this give me no preference for the bits & your way is
as good as any other.
We might as well go with it.
Dan