ISO Prolog(ID:3556/iso001)

Prolog conforming to the ISO Prolog standard> Work began 1985, WG started 1987, Ballot 1997.

ISO/IEC JTC1/SC22/WG17 N155
Related languages
Prolog => ISO Prolog   Standardisation
References:
  • Bagnara, Roberto "Is the ISO Prolog standard taken seriously?" The Association for Logic Programming Newsletter 12(1) February 1999 pp10-12 view details Abstract: During the development of a CLP multi-language software tool I discovered that the ISO Prolog standard is essentially disregarded. This happens even for the most widespread and influential Prolog/CLP implementations, even in their most recent versions, and even if we look at syntax only. For instance, let us take X-Prolog to range over "SICStus Prolog 3.7.1", "SWI-Prolog 2.8.1", "BinProlog 5.75", "you name it". Then it appears that:
    an ISO Prolog program is not an X-Prolog program;
    an X-Prolog program is not an ISO Prolog program.
    It also seems that, even in most recent versions, choices have been made that will make future conformance to the standard very difficult, if not impossible at all. In other words, features that go openly against the standard are not even deprecated in the documentation of most systems. Users are thus encouraged to use these features. They will write code using them. Who will then dare to break backward compatibility?

    For these reasons, I think I can give an answer to the question in the title of this writing: no, generally speaking, the ISO Prolog standard is not taken seriously (there are exceptions, of course: for instance, the developers of B-Prolog appear to seek for standard conformance).

    Another question naturally arises, and this is the question that urged me to write the present note:

    Is the ISO Prolog standard to be taken seriously?
    I read comp.lang.prolog regularly, I subscribed the "users" mailing list for several major Prolog programming systems, and I regularly visit the WWW sites dedicated to logic programming. But I have never seen somebody complaining because some Prolog vendor/provider was ignoring the standard. So, unless something important has escaped my attention, the above question is legitimate. After all, a standard that nobody cares about, in practice, does not exist.

    With this note I intend to solicit opinions from everybody in the community: a question like this must not pass under silence and an answer, any answer, can save the time of many people.

    External link: Online copy
    Resources