RE: ISAC: IRs to review and a question about IR 2031

Chuck,

Thanks for updating the IRs. I'm happy with the revised wording.

Re IR2031: I agree that the passages you quote don't make sense an should be
deleted from the IR. The LRM states that physical types represent
measurements of quantities, and that arithmetic operations on these types
have their conventional mathematical meaning.  That implies the operations
are done in terms of the abstract quantities, and the result may be
expressed in whatever units you like.  The choice of units does not affect
the result of the operation.

End $0.02.

Cheers,

PA

--
Dr. Peter J. Ashenden                        peter@ashenden.com.au
Ashenden Designs Pty. Ltd.                   www.ashenden.com.au
PO Box 640                                   Ph:  +61 8 8339 7532
Stirling, SA 5152                            Fax: +61 8 8339 2616
Australia                                    Mobile: +61 414 70 9106


> -----Original Message-----
> From: owner-isac@eda.org [mailto:owner-isac@eda.org] On 
> Behalf Of Chuck Swart
> Sent: Wednesday, 11 May 2005 05:34
> To: isac@eda.org
> Subject: ISAC: IRs to review and a question about IR 2031
> 
> 
> I am attaching 6 updated IRs which I have not
> yet added to the ISAC data base.
> Please review them.
> IR2020, 2031 and 2061 have rewording which you might want to improve.
> 
> IR2029, 2044 and 2059 are very straightforward.
> 
> Note that Peter updated IR2053 during the ballot phase.
> 
> If I don't receive any suggestions in the next couple of 
> days, I'll put them into the database.
> 
> I have a question about IR2031: "mod" function needed for TIME
> 
> The IR states:
> 
>       The units of the result of a mod operation are left to the
>       implementation as long as the result satisfies the above
>       relation.
> 
> and  
>       The units of the result of a mod operation are left to the
>       implementation as long as the result satisfies the above
>       relation.
> 
> My question is: Are these statements really necessary?
> We don't make any statements about other expressions 
> involving time, such as 5ns + 2ps. Why do we need to say 
> anything in the LRM about units 
> for 5ns mod 2ps?
> Technically, all these values are computed using either the 
> primary unit 
> (fs) or using the resolution limit,
> so why do we need to say anything more?
> 
> 
> Chuck Swart
> 
> 
> 
> 
> 
> 
> 
>