A motion 33 query
Vincent
The discussion on Motion 33, includes an exchange between Dmitry and yourself, see below. I also had thought the motion text doesn't make it clear enough that (B1)-(B4) are not about what an IEEE number format *is*, but about how it binds to P1788, or rather to (A1)-(A5).
You said Dmitry's proposed emendation to the wording, "The notion ... binding to (A1)-(A5)" is a good one. Should we take it that the motion now includes these words? The version currently on the P1788 Motions web page doesn't include them.
John Pryce
On 17 Apr 2012, at 14:26, Dmitry Nadezhin wrote:
> Vincent,
>
> Thank you for your answer. No I understand your suggestions better.
>
>>> 5) Do your (B1)-(B5) definitions define "number format" format as a
>>> finite subset set of floating-point data (Level 2 of IEEE754-2008 ) ?
>>
>> No, it must also be a 754 format (Level 2) as specified by Motion 6.04,
>> well, except that here, one may want to distinguish +0 and -0. But this
>> should be done by later motions. I suspect that in input, there will be
>> no differences between +0 and -0 for P1788. But IMHO, if a sup(X) or
>> mag(X) is 0 at Level 1, then it must have the + sign. And for a format F
>> as mentioned in B4, the rounding rules must be the ones of IEEE 754,
>> where the sign of 0 is specified.
>>
>> B1-B3 mainly specify bindings to IEEE 754-2008.
>
> I think that the motion should say this in more clear way.
> I misunderstood this section initially. I think that some othere reader can misunderstand too.
> Why not say:
> <<<
> The notion of a 754-conforming implementation has been introduced
> in Motion 6.04. A 754 format is one of the number formats defined in IEEE 754-2008
> with the following binding to (A1)-(A5):
> >>>