Editing ALGOL 68 (section)

===Definition process===
The first meeting of the ALGOL X group was held in [[Princeton University]] in May 1965. A report of the meeting noted two broadly supported themes, the introduction of [[strong typing]] and interest in [[Euler programming language|Euler's]] concepts of 'trees' or 'lists' for handling collections.{{sfn|Lindsey|1993|p=9}} Although intended as a "short-term solution to existing difficulties",{{sfn|Lindsey|1993|p=4}} ALGOL X got as far as having a compiler made for it. This compiler was written by [[Douglas T. Ross]] of the [[Massachusetts Institute of Technology]] (MIT) with the ''Automated Engineering Design'' (AED-0) system, also termed ''ALGOL Extended for Design''.<ref>{{Cite web |last=Ross |first=Douglas T. |date=October 1966 |url=http://www.dtic.mil/cgi-bin/GetTRDoc?AD=AD0296998 |archive-url=https://web.archive.org/web/20130626171225/http://www.dtic.mil/cgi-bin/GetTRDoc?AD=AD0296998 |url-status=dead |archive-date=26 June 2013 |title=An Algorithmic Theory of Language (AB26.2.2) |page=6 |website=Defense Technical Information Center |publisher=Massachusetts Institute of Technology |access-date=2020-08-12}}</ref><ref>{{Cite journal |last=Ross |first=D. T. |date=August 1967 |url=https://dl.acm.org/doi/abs/10.1145/1139498.1139500 |title=AB26.2.2 Features Essential for a Workable ALGOL X |journal=ACM SIGPLAN Notices: ALGOL Bulletin |volume=26 |issue=2 |publisher=Association for Computing Machinery: Digital Library |doi=10.1145/1139498.1139500 |s2cid=38156680 |access-date=2020-08-12|url-access=subscription }}</ref>

At the second meeting in October in France, three formal proposals were presented, [[Niklaus Wirth]]'s [[ALGOL W]] along with comments about record structures by [[C.A.R. Hoare|C.A.R. (Tony) Hoare]], a similar language by Gerhard Seegmüller, and a paper by [[Adriaan van Wijngaarden]] on "Orthogonal design and description of a formal language". The latter, written in almost indecipherable "W-Grammar", proved to be a decisive shift in the evolution of the language. The meeting closed with an agreement that van Wijngaarden would re-write the Wirth/Hoare submission using his W-Grammar.{{sfn|Lindsey|1993|p=9}}

This seemingly simple task ultimately proved more difficult than expected, and the follow-up meeting had to be delayed six months. When it met in April 1966 in [[Kootwijk]], van Wijngaarden's draft remained incomplete and Wirth and Hoare presented a version using more traditional descriptions. It was generally agreed that their paper was "the right language in the wrong formalism".{{sfn|Lindsey|1993|p=24}} As these approaches were explored, it became clear there was a difference in the way parameters were described that would have real-world effects, and while Wirth and Hoare protested that further delays might become endless, the committee decided to wait for van Wijngaarden's version. Wirth then implemented their current definition as ALGOL W.{{sfn|Lindsey|1993|p=10}}

At the next meeting in [[Warsaw]] in October 1966,<ref>{{Cite web|url=http://archive.computerhistory.org/resources/text/algol/algol_bulletin/|title = The Algol Bulletin}}</ref> there was an initial report from the I/O Subcommittee who had met at the [[Oak Ridge National Laboratory]] and the [[University of Illinois]] but had not yet made much progress. The two proposals from the previous meeting were again explored, and this time a new debate emerged about the use of [[pointer (computer science)|pointers]]; ALGOL W used them only to refer to records, while van Wijngaarden's version could point to any object. To add confusion, [[John McCarthy (computer scientist)|John McCarthy]] presented a new proposal for [[operator overloading]] and the ability to string together ''and'' and ''or'' constructs, and [[Klaus Samelson]] wanted to allow [[anonymous function]]s. In the resulting confusion, there was some discussion of abandoning the entire effort.{{sfn|Lindsey|1993|p=10}} The confusion continued through what was supposed to be the ALGOL Y meeting in [[Zandvoort]] in May 1967.{{sfn|Lindsey|1993|p=9}}