Beefy Boxes and Bandwidth Generously Provided by pair Networks
go ahead... be a heretic

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
Ovid, in prolog, attributed variables is what you are looking for.

Attributed variables are unbound variables but with a set of conditions or attributes attached. When an attributed variable is unified with anything else, its attached attributes (that are effectively callback predicates) are called, and their success or failure determines also the success or failure of the unification.

Most free prolog implementations (SWI-Prolog, YAP, XSB ) support them (unfortunately Language::Prolog::Yaswi doesn't), and it should be too difficult to extend AI::Prolog to also do so.

Attributed variables are mostly used in prolog to implement constraint logic programing (CLP). A good introduction to CLP is available on Bratko's Prolog Programing for Artificial Intelligence.

In reply to Re: (OT) Pushing inductive systems to their limit by salva
in thread (OT) Pushing inductive systems to their limit by Ovid

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others pondering the Monastery: (8)
    As of 2015-11-27 10:50 GMT
    Find Nodes?
      Voting Booth?

      What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

      Results (724 votes), past polls