🚀 go-pugleaf

		An Annotated Version of PS/27.

    PS/27 is document number 27 is the BSI Prolog Standardisation effort's
document register.  You don't produce a British Standards Institute standard
just by saying you have got one; you have to persuade the BSI to lend you
their name.  One of the steps you have to take in this process is to write
a formal "Proposal to BSI for new standardization work", which says what
you intend to do and why you think the BSI should lend their name to it.
It's a little bit like a contract, and a whole lot like a promise.

    The rest of this text is an annotated version of PS/27.  There is no
copyright notice on any part of PS/27.  Three kinds of text appear here:
(B) Material which is part of the BSI form 11-8405.
(P) Material which is specific to PS/27.
(%) My remarks.
Punctuation and spelling are copied from the original.

B	Proposal to BSI for new standardization work.

B	Part A Proposer and Supporters

B	1 Name and address of proposer
P		R S Scowen,
P		National Physical Laboratory,
P		Teddington, Middlesex.

B	2 Name(s) and address(es) of body(ies) supporting the proposal
P		Alvey Directory; CCTA; Department of Trade & Industry;
P		University of Edinburgh; Imperial College, London;
P		International Computers Ltd; British Gas; British
P		Standards Institute Quality Assurance Division; etc.

B	3 Date of submission
P		January 1985

B	Please submit with this Form letters from the bodies indicating
B	the degree of support expected, eg in committee work, drafting,
B	research, commitment to use the standard.

%	No such letters were attached to PS/27, nor have any been sent
%	to me separately, either before or since.  No doubt such letters
%	exist and were sent to the BSI; I merely indicate why I cannot
%	comment on them.

B	Part B. The Proposal

B	1 Explain the economic, commercial/industrial, safety, consumer
B	protection or other benefits of the proposal.  Why is
B	standardization needed?
P	Rapid growth in adoption of Prolog is leading to many different
P	processors being developed and marketed.  Standardization will:
P	* Permit portable code to be developed,
P	* Aid transfer of personal knowledge and experience.
P	* Encourage wider adoption of these important ideas and techniques.
P	* Help maintain UK in its strong position.
P	* Help the Alvey programme achieve its objectives of better
P	  communications and co-operation between UK groups by discouraging
P	  fragmented and isolated efforts.

B	2 Is the standard required or likely to be required for regulatory
B	purposes?  If yes, please specify relevant legislation.
P	Not foreseen initially.

B	3 Is the standard required or likely to be required for purchasing
B	purposes?  If yes, please specify.
P	Yes

%	PS/27 does not specify any further.  This much seems clear:  the
%	intent is that "Prolog" processors conforming to the BSI substandard
%	should enjoy a commercial advantage over other "Prolog" processors.

B	4 Is third party certification in view?
B	If yes, please indicate by which body or bodies
P	Yes.  BSI Quality Assurance Division intend to offer a validation
P	service for Prolog processors in the same way as they now do for
P	Pascal.

%	This is an interesting one.  At one point, Expert Systems International
%	offered to adapt their own regression-testing suite to BSI Prolog to
%	serve as the basis of such a validation suite.  At a later time, it
%	was apparently decided that developing a validation suite was not a
%	task for the BSI Prolog committee.  I do not know what the current
%	status of the validation suite is.  Myself, I think they should have
%	developed the validation suite first, and used it to check the
%	standard.  I suggested that the DEC-10 Prolog library be a part of
%	this suite.  (I've not seen this mentioned anywhere, so they may have
%	"lost" this suggestion.)

B	Part C Definition of the standard requested

B	1 What is the proposed title?
P	Specification for computer programming language Prolog.

B	2 What is the proposed scope?
P	To specify the syntax and semantics of the language Prolog by
P	specifying the requirements for Prolog processors and programs
P	including Prolog library modules and aspects of the Prolog
P	environment.

%	I'm not quite sure what this means.  Do they mean that the effect
%	of Prolog library modules is to be specified, the way that the C
%	library is part of the draft ANSI C standard?  (This is not what
%	they have done.)  More plausibly, they mean that they will
%	specify what a standard-conforming library module must be like,
%	as a special case of what a standard-conforming program must be
%	like.  The current draft fragments do impose some fairly strong
%	restrictions on the environment (UNIX and MS-DOS can satisfy them
%	but VM/CMS can't).

B	3 Which type of publication is proposed:
B	Note 2.	A "specification" should be drafted only when the
B		intention is to specify requirements for compliance
B		such that compliance can be objectively and
B		unambiguously claimed and verified.  The description
B		'Specification' should not be used in the titles of
B		documents designed for other purposes.
P	Specification.

B	Part D Drafting and timescale

B	1 When could a first draft be made available to BSI?
P		End of 1985
B	Who would provide it?
P		It will be provided by an existing working group.

%	I do not know whether a first draft has ever been made available
%	to the BSI.  There have been several drafts of the syntax so far,
%	and many drafts of different groups of built-in predicates, but I
%	have not yet received a single document purporting to be a first
%	draft of a BSI standard for the whole language.  There WAS a PS/3
%	purported to be a first draft of a standard, but it predated the
%	"Proposal for new standardization work", and PS/5 (which I was
%	commenting on in December 84) had already made it clear that
%	PS/3 would NOT form the basis of BSI Prolog.  To quote PS/5,
%	PS/3 "in many cases defines neither their meaning nor their
%	effect".  So I assume that PS/3 cannot be the first draft that
%	PS/27 promised.

B	2 Will the project depend upon research and development work now
B	in train or yet to be started?  If yes, please give details.
P	No.  The content of the standard will be based on Edinburgh Prolog
P	as described in Programming in Prolog by W F Clocksin & C S Mellish
P	Spring 1981.

%	This is the statement which Chris Moss said he couldn't find.
%	Note that it says clearly:
%	(a)  No research and development work either in progress or yet
%	     to be started will be depended on.  At the time, I took this
%	     to promise that they would be trying to standardise practice
%	     as it stood in January 1985, not to invent a new language.
%	(b)  The CONTENT of the standard is to be based on Edinburgh
%	     Prolog, as described in Clocksin & Mellish.  At the time, I
%	     was so naive that I took this to mean that the standard was
%	     to be based on Edinburgh Prolog.

B	3 What is the latest date by which the project should be complete
B	if it is to be of optimum use?
P	For optimum use, a standard is required as soon as possible but
P	no later than 1986.  An international standard will be required
P	soon afterwards.

%	No later than 1986.  It could have been done, that's the sad thing.
%	If they had kept their promise, it could have been done.

-------------------------------

That's the end of the BSI form, but there is an attachment.

The attachment says, amongst other things:

P	An informal working group has been formed and already set to work
P	on a British Standard.  The group has representatives from all
P	major centres of expertise in Prolog together with experts in
P	programming language standardization and language certification.
P	The group regards this matter as urgent and aims to produce a
P	draft by the end of the year.

%	Note:  "representatives from" does not mean "skilled representatives
%	from".  One of the "representatives from" a "major centre of
%	expertise in Prolog" told me that his professor had sent him as
%	his substitute because his professor was too busy.  I gave him his
%	first lesson in Prolog data structures, some months AFTER he had
%	started attending meetings.

%	Note:  "all main centres of expertise" did not at that time
%	include any outside the UK.  Nobody from Waterloo, nobody from
%	Melbourne, nobody from Japan, nobody from Israel, *not*one* of
%	the developers of DEC-10 Prolog, nobody from Syracuse, and so on.

P	The interest in logic programming and Prolog makes it inevitable
P	that a standard Prolog will be defined and adopted sooner or
P	later.  By initiating this process in the UK, we will be able to
P	exert influence on the resulting standard and strengthen Britain's
P	position in this important new area of Information Technology.
P	We will also be able to foster UK implementors.

%	Note that last sentence:  the goal is to foster UK _implementors_.
%	And that's exactly what is happening, even at the expense of Prolog
%	_users_ in the UK and worldwide.

--------------------------------