Since I brought up the topic, I thought I'd clear it up. :)
The book "History of Programming Languages", edited by Richard L. Wexelblat,
contains papers and transcripts of talks given by Alan J. Perlis and Peter
Naur about the development of ALGOL {58-60} language.
Naur is describing his participation in the December 1959 meeting
of the European part of the ALGOL committee.
"The use of Backus's notation could only be mentioned in passing;
my recommendation to that effect appears as one of 55 brief notes
on revisions of the Zurich report as follows: '15) Change the syntactical
description'" "The decisive action concerning the development of the
new style of description was taken during the weeks following the
Mainz meeting, when I worked out the results of the meeting according
to the notions of language description that I had formed. In order
to press the matter forward as much as possible, on January 2 I sent
all other committee members a document... [which] contains the first
appearance of my slightly revised form of Backus's notation."
In an appendix, Naur discusses how he modified Backus's notation
by giving a brief example. Personally, I was stunned at how trivial
the changes were: basically, he modified the language so that it included
only symbols you could type at a standard keyboard. Naur concludes with
this comment:
"Thus the modified notation uses ::= instead of [can't type this
symbol: it's a colon followed by an equals sign with a third line
above it] and | instead of [another symbol that can't be typed: it's
the keyword or with a line above it]. In addition, in the modified
form the designations of the syntactic constituents, such as 'basic
statement,' are chosen to be exactly the same as those used for the
same items in describing the semantics, without abbreviation."
In a later appendix, F. L. Bauer responds to Naur's statements:
"It is amusing to see how Peter Naur looks at the use of the Backus
notation from his personal point of view. Among [other members of
the committee] there was no question that we would like... a form
similar to the one Backus had used for its ICIP paper... If Peter
Naur had seen this a result of his "plan" to make an appeal to the
members of the ALGOL committee concerning the style of the language
description, he was running into open doors."
"... Peter Naur speaks of 'my slightly revised form of Backus's notation'
and 'my slightly modified form of Backus's notation.' I think the
minor notation difference is not worth mentioning. If some people
speak of Backus- Naur form instead of the original Backus Normal Form,
then they indicate that Peter Naur, as the editor of the ALGOL 60
report, brought this notation to a wide attention. Backus-ALGOL Form
would be more appropriate anyhow."
Here are K. Samuelson's comments on Naur's statements:
"On the subject of BNF (which to me has always meant Backus Normal
Form, since John Backus quite alone introduced it in his Paris '59
paper) for the ALGOL 60 report, I can only contradict him. As far
as I, or even the entire GAMM group, is concerned no persuasion whatsoever
was necessary to use it. Rather, BNF just needed to be presented by
John to be accepted as a superior means of syntax description."
The following exchange comes from a transcript given at the 1978
conference which the book documents:
CHEATHAM: The next question is from Bernie Galler of the University
of Michigan, and he asks: "BNF is sometimes pronounced Backus-Naur-Form
and sometimes Backus-Normal- Form. What was the original intention?
NAUR: I don't know where BNF came from in the first place. I don't
know -- surely BNF originally meant Backus Normal Form. I don't know
who suggested it. Perhaps Ingerman. [This is denied by Peter Z. Ingerman.]
I don't know.
CHEATHAM: It was a suggestion that Peter Ingerman proposed then?
NAUR: ... Then the suggestion to change that I think was made by Don
Knuth in a letter to the Communications of the ACM, and the justification
-- well, he has the justification there. I think I made reference
to it, so there you'll find whatever justification was originally
made. That's all I would like to say.
