Subject: WG11 N407 - Minutes of WG11 meeting, January 1995

From: Willem Wakker <[email-masked]>
Date: Mon, 20 Feb 95 12:37:11 N

DRAFT MINUTES OF MEETING		      SC22/WG11/N407

Committee:   ISO/IEC JTC1/SC22/WG11

Place:	     Digital Equipment Corporation
	     Maynard, U.S.A.

Date:	     January 30 - February 3, 1995

Attendees:   Mr. Ed Barkmeyer	      NIST, USA.
	     Mr. Robert Eachus	      MITRE Corporation, USA
	     Mr. Kevin Harris	      DEC, USA
	     Mr. Randy Hudson	      Intermetrics Inc, USA
	     Prof. Katsuhiko Kakehi   Waseda University, Japan
	     Mr. Kent Karlsson	      Chalmers University of Technology, Sweden
	     Mr. Brian Meek	      King's College London, UK
	     Ms. Mary Payne	      DEC, USA
	     Mr. Paul Rabin	      OSF, USA
	     Mr. Craig Schaffert      DEC, USA
	     Mr. Willem Wakker	      ACE, Netherlands (Convener)

1.  Agenda (WG11/N402)

It was agreed to handle the various topics in the following order:

Monday afternoon:   Opening, reports, alignment LIPC/RPC
Tuesday:	    LID ballot resolution
Wednesday:	    LIA-2
Thursday:	    LISS
Friday: 	    Round-up, close of meeting

2.  Minutes of Previous Meeting (WG11/N395)

The minutes were approved.

3.  Convener Report

The new delegate from Japan was welcomed: WG11 looks forward to a fruitful
cooperation with the Japanese experts.

The convener reported on two important issues from the last SC22 Plenary
(September 1995):

  1.  The SC21 Plenary had decided in August 1994 to replace the RPC
      specification that had been under production (in cooperation with
      WG11) by the completely different X/Open DCE/RPC specification.  The
      effect is that the alignment between LIPC and RPC is completely
      destroyed.

      SC22 instructed WG11
	 - to investigate the differences between the new RPC specification
	   and LIPC,
	 - to report back to SC22 on this issues, and
	 - not to progress LIPC to the next stage until this investigation
	   was completed.

      It was noted with great dismay that still no official notification of
      the change of plans of SC21 was received by either SC22 or WG11.

  2.  With JTC1 ballot on LISS, 6 countries indicated that they would
      participate actively in the work (Denmark, Germany, Japan,
      Netherlands, Roumania and UK).  However, Germany, Japan and Roumania
      are not active in WG11, and Denmark is only marginally active.  This
      means that the active participation on this project is questionable.
      The US voted NO on the project, although the projected project-editor
      comes from the US.

      It was decided at the SC22 plenary that Germany and Japan would
      nominate experts for active participation, and that an attempt would
      be done to start with the project.

      It was noted that Germany has not yet nominated an expert.

4.  National Activity Reports

4.1  BSI IST/5/11, Report by Brian Meek

The UK panel remains active but has mainly operated by electronic mail
since the last WG11 meeting, though a meeting was held on 10 January 1995
to review the WG11 agenda and in particular review the LIA-2 draft, which
the UK had been pleased to see.  We are glad to report that John Dawes is
now back at work in the panel and in the parent (SC22 level) committee.  In
that regard, it should be noted that John is still active in PCTE and is
forming a UK panel to shadow WG22, and has expressed himself willing to act
as liaison between WG11 and WG22 if both WGs think that is a good idea.

4.2  ANSI X3T2, Report by Craig Schaffert

Since the last WG11 meeting, X3T2 has concentrated on Conceptual Schema
Interchange work.  X3T2 did formulate comments on LID and LIPC, but
progress in LIA and LISS has been left to the respective editors.

4.3  Report from the Japanese WG11 group by Katsuhiko Kakehi

The Japanese WG11 group was recently revitalized, and has now 9 members.
At this point in time, their main activity is to get familiar with the
various WG11 projects.

It is the opinion in Japan that the language independent work should get
more emphasis in SC22.

5.  Work Item 22.16 - Language Independent Procedure Calling

At the last meeting (April 1994), the comments on the CD ballot on LIPC
were discussed, and a new draft of the document was prepared by the
convener to be forwarded for DIS ballot.  However, during the SC22 plenary,
WG11 was instructed to first study the issue of alignment with RPC, before
the next stage was entered.

No official version of the new RPC document was received by WG11, only
drafts of some parts were available.

It was decided that an informative annex to LIPC will be produced,
describing in an informal way the relationship between the LIPC and the
RPC.

The differences between the LIPC-IDN and RPC-IDL are not very serious;
however, since the RPC-IDL clearly describes a subset of the more general
LIPC mechanisms, it is not possible to incorporate the RPC-IDL in the LIPC
specification, as this would imply a limitation on the LIPC as it stands.
Adoption of the RPC-IDL would also have serious consequences for the LID-
IDN (which is a subset of the LIPC-IDN).

The suggestion to include in this process also the CORBA IDL was rejected
for the following reasons:  the status of the CORBA specification within
ISO is unclear, and the alignment between 2 specifications under
consideration by SC21 (RPC and CORBA) is really an SC21 matter.

As soon as the annex is available, the LIPC document will be forwarded to
JTC 1 for DIS ballot.

Milestones for the LIPC project:

2.8   93-10   WD approved for registration as CD
3.0   93-11   CD registered
3.8   94-10   CD approved for registration as DIS
4.1   95-03   DIS ballot initiated

6.  Work Item 22.17 - Language-Independent Datatypes

The DIS 11404 was approved by JTC 1 (closing date of the ballot was
October 16, 1994) with 15 YES votes and 5 (Australia, Canada, Germany,
Japan and USA) NO votes (WG11/N403).

The comments were discussed, details can be found in the disposition of
comments document (WG11/N408, to be produced).

The final version will be sent by the end of February 1995 to ITTF for
publication.

Milestones for the LID project:

2.8   91-01   WD approved for registration as CD
3.0   91-05   CD registered
3.1   91-05   CD study initiated
3.8   93-10   CD approved for registration as DIS
4.1   94-04   DIS ballot initiated
4.8   95-03   Full report circulated and DIS approved for publication as IS

7.  Work Item 22.28 - Language-Independent Arithmetic, Part 1: Integer and
    Floating Point Arithmetic

The IS was published by ITTF in 1994.

8.  Work Item 22.33 - Language-Independent Arithmetic, Part 2: Language
    Independent Mathematical Procedure Standard

A first working draft of LIA-2 (WG11/N404) was discussed extensively.
Topics were:

   - change the title of part 2 to "Elementary Numeric Functions."  The
     title of part 3 would presumably be changed to match.  This will be
     further discussed via email.

   - standardize the evaluation of expressions.  This is a major work item,
     not currently in the LIA-2 scope, and should thus be developed as a
     separate work item.  Maybe LIA-4?

   - Conformity: allow implementations to conform to individual functions
     or groups of functions.  The conformity clause should be base the
     conformity clause on the LIA-1 text.

   - Scope / What functions to include:

	o Include the elementary numerical functions from existing or
	  proposed standard languages.
	o Do not include intricate functions such as matrix inversion --
	  even though Basic does.
	o Large separable groups of functions (such as matrix arithmetic or
	  statistical functions) deserve to be handled as separate parts of
	  LIA.
	o Include detailed radix and type conversions.
	o Include functions to help define conversions to and from textual
	  forms.  Definitely decimal, possibly other radices.  Note that
	  these functions are intended to handle the radix conversion and
	  rounding issues, not formatting.
	o Include reasons in the rationale.
	o Exclude functions that just "move values around" rather than
	  compute.  Example: min and max.
	o Generally avoid simple compositions of existing functions.
	  Particularly mixed mode functions.  We don't need to get into
	  defining all the possible combinations.
	o Compositions that add something (like guaranteed single rounding)
	  are reasonable candidates.
	o Try to use single definitions and variants when possible.
	  Example: the trig functions in degrees in the first draft.
	o Generalize hypot to euclidean-norm?  How do we handle varying
	  numbers of arguments?

   - Required accuracy: there was a general feeling that 1/2 ulp accuracy
     on all functions would be nice, but very expensive.  We would need a
     strong argument that acceptably efficient algorithms are available for
     each function so specified.

     The opposite extreme is to permit any accuracy to conform, and require
     runtime accessible parameters which characterize the maximum error.
     This was also rejected as unnecessarily permissive.

     LIA-2 will stipulate a maximum permitted error for each function.
     These will be stipulated independently, but may fall into natural
     groups.  Runtime information will be required.

     The Ada functions package will provide some information on achievable
     accuracy.

   - Runtime parameters: a simple "max error over the whole domain"
     parameter seems feasible for all the functions that we are currently
     considering.  A more complex approach such as an "error at a given
     point" function is much harder to provide.  Since simple solutions are
     preferred, we will require a single max-error parameter for now.

   - Form of specifications: don't define mathematical functions such as
     sine.  Assume them instead.

     Specify how functions behave when given NaNs and Infinities as
     arguments.  Specify when NaNs and Infinities shall be produced as
     results.  Such specifications shall hold whenever the implemented
     floating point types have such values.

     Be compatible with the NCEG work as much as possible.

     Axioms requiring certain exact values to be returned are OK.

     Monotonicity falls out naturally from many implementations of single
     argument functions and is useful.

   - Notification: adopt the LIA-1 model and requirements with additional
     exception names.

     An "argument too large" notification is tentatively accepted for the
     basic six trig functions.	More discussion is needed.

     Most overflow and underflow boundaries appear to be exact.  If so, no
     provision for "fuzzy" notification boundaries is needed.  But this
     needs further analysis.

It is planned to have an updated version before the next meeting, and a WD
for CD registration by September 1995

Milestones for the LIA Part 2 project:

2.1   91-09   WD study initiated
      94-11   First draft circulated
2.8   95-09   WD draft for CD registration

9.  Work Item 22.34 - Language-Independent Arithmetic, Part 3: Language
    Independent Complex Arithmetic and Procedure Standard

No progress made.  The planning of this work follows the planning for LIA-
2, with a delay of one year.

Milestones for the LIA Part 3 project:

2.1   91-09   WD study initiated
      95-11   First draft circulated
2.8   96-09   WD draft for CD registration

10.  Work Item 22.46 - Language-Independent Service Specifications (LISS)

Despite the limited support by National Bodies it was decided to continue
the project.  The motto for the project will be "provide guidelines and
provide them quickly".	This means that we should take the TCOS document
(N392) and adapt it to LID/LIPC, and do not do any serious and time
consuming development.

Based on commitments by the project editor and the UK WG11 panel, an
aggressive timeschedule was agreed, which should lead to a WD for CD
registration by the end of September 1995.

Milestones for the LISS project:

2.1   94-04   WD study initiated
      95-04   First draft circulated
2.8   95-10   WD draft for CD registration

11.  Planning and Future Meetings

May 29 - June 2, 1995	Amsterdam   Issues: LIA-2, LISS

September 1995		USA	    Date and place to be fixed.
				    Preferably immediately before or
				    after the SC22 plenary in Annapolis
				    (September 18-22).
				    Issues: ballot comments on LIPC,
				    LIA-2, LISS

12.  Close of Meeting

The host, Digital, was thanked for organizing the meeting.

13.  Documents identified since last mailing

  _______________________________________________________________________
  WG11	 Other	 Author     Title
  _______________________________________________________________________
  404		 Editor     Draft LIA-2
  405			    Resolution ballot comments on CD 13886 (N394)
  406		 Convener   Meeting announcement WG11 meeting May 1995
  407		 Convener   Minutes WG11 Meeting January 1995
  _______________________________________________________________________