Comment by triska | Hacker News Reader

Comment by triska | Hacker News Reader

Thank you very much for the publicity, I greatly appreciate it!

This book has been discussed on HN about one year ago:

https://news.ycombinator.com/item?id=14045987

Since then, I have added the following new chapters:

Prolog Business Cases: https://www.metalevel.at/prolog/business

Sorting and Searching: https://www.metalevel.at/prolog/sorting

Cryptography with Prolog: https://www.metalevel.at/prolog/cryptography

Engineering Aspects: https://www.metalevel.at/prolog/engineering

Artificial Intelligence with Prolog: https://www.metalevel.at/prolog/ai

I have also made many improvements and additions to the other chapters.

Also, I have made almost everything available in a public git repository so that you can track the book's progress and view it offline:

https://github.com/triska/the-power-of-prolog

It is my sincere hope that you find this material useful, and I welcome all suggestions and comments.

Also, thank you very much to all readers for the extremely constructive feedback that I have received in the past year. Your comments have made this work especially worthwhile.

Enjoy!

I've shared this with anyone who will let me divert the conversation to Prolog. At work we have the Haskell folks, the Lispers who move everything towards Lisp, and I'm the one who moves every conversion towards Prolog, then I send the link to this. :-D

Where do you work? Sounds neat!!

It sounds like a level of Hell that Dante forgot to mention.

what makes you feel that way?

Malbolge maybe?

Thank you for sharing this, I really appreciate you participating in this thread and this awesome anecdote!

One related workplace anecdote that a former fellow student told me: He was working on a rule-based medical recommender system, and he recognized that Prolog was an excellent fit for this project. When he first suggested that the team switch to Prolog, they were very skeptical. But someone high up in the chain was a great fan of Prolog and approved this suggestion. A few weeks later, they had completed the implementation, and the Prolog-based solution was running. My colleague told me that, a few months after that, the whole team regarded Prolog as the only viable solution to all further projects from then on!

> My colleague told me that, a few months after that, the whole team regarded Prolog as the only viable solution to all further projects from then on!

Hm, there is such a thing as the right tool for the job. If all their jobs were very similar that makes sense, otherwise, not so much.

Are you aware of the fact that inside every Windows NT installation there was a Prolog engine to help with network configuration?

http://web.archive.org/web/20040603192757/research.microsoft...

Personally, I found this the fun aspect of this story: that what one regards as "the" (as opposed to a) right tool for the job can change so quickly, and can so strongly depend on one's perspective!

Thank you for the link to the Prolog-based network configuration!

The older Lisp folks often have a Prolog integrated in their system...

Mini-kanren?

Prolog

Actual Prolog. Allegro ships a fully integrated Prolog as part of their product.

Now that you say that i think both Allegro and Lispworks both have that...neat!

And the Haskell folks have list application and filtering that is equivalent to the Prolog search algorithm.

PicoLisp has one.

If you are talking about the Pilog "Prologue Engine" it really is not the same thing at all as a proper Prolog.

Oh, I was honestly not aware. Now I know to look for differences. You don't have to, but could you give some pointer or clue as to why PicoLisps prolog engine is not a proper Prolog?

> I send the link to this. :-D

And what kind of reaction are you getting? As I just wrote elsewhere, I don't think this is useful for complete Prolog beginners to learn the language or even get a feel for it. Has anyone you sent this to come back with "that's neat, I read the first N chapters and have just written my first Prolog program on my own"?

Yes, but we are stuck in our ways. We like all sorts of languages, some for instance talking enough about J got me learning J. Someone else not shutting up about rust got me looking into rust. Me not shutting up about golang got other's to check it out. I got the entire company on typescript instead of javascript. :-) Our normal tech stack is pretty boring and safe. But I'm glad there's a few folks who are open minded and trying something else. No one has used prolog in production that I know of but me. I used it to validate some business rules.

I studied some Prolog and Haskell in the undergraduate days. Well now my work is mostly done in Java, e.g Android.

What are strong cases to use Prolog/Haskell these days? :D

Prolog-ers and Lispers are friends <3

ebony and ivory / live together in perfect harmony

etc

Where do you work that you get so little imperative languages?

A section on dynamic programming w.r.t. to modern AI techniques would complement it nicely considering the resurgence of the field :D

Thank you, this sounds like a wonderful addition!

In general, the AI chapter is what I am currently working on most. I mean not "only" on the actual content, but on the applications I want to present in this chapter.

Anton Kochkov has recently motivated this chapter via a dedicated issue for AI/ML applications of Prolog, and I invite you to track its progress at:

https://github.com/triska/the-power-of-prolog/issues/5

Hi Markus, thanks for your hard work on this website (also on all the Swi constraint libraries).

For your machine learning section, you might want to consider discussing Metagol [1], a modern ILP system that can learn recursive theories and perform predicate invention.

The core Metagol implementation is tiny and relies on a meta-interpreter (the technique is called Meta-Interpretive Learning). It is a radically different approach to previous ILP systems but much simpler and easier to understand. It should be interesting to anyone who wants to do machine learning with Prolog.

____________

[1] https://github.com/metagol/metagol

Thank you very much Stassa!

I have added Metagol to the AI chapter, please have a look.

That looks great, cheers! :)

Very nice book. Do you know what companies are using prolog commercially?

Thank you for the kind words!

Regarding companies that use Prolog, here are a few examples:

A third of all airline traffic is handled by systems that run SICStus Prolog:

https://www.sics.se/projects/sicstus-prolog-leading-prolog-t...

A large portion of the New Zealand stock exchange is powered by Prolog:

https://dtai.cs.kuleuven.be/CHR/files/Elston_SecuritEase.pdf

Oracle uses Prolog in the JVM specification:

https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-0-pr...

IBM has used Prolog for natural language processing in Watson:

https://www.cs.nmsu.edu/ALP/2011/03/natural-language-process...

RedPrairie uses SICStus Prolog for optimization tasks.

Prolog is used for voice processing on the International Space Station.

Windows NT used to have a Prolog based system for handling interrupts, not sure how much of it is still relevant on W10.

I was pretty sure that it was for configuring network devices.

Actually, I think we are both right.

http://collaboration.cmc.ec.gc.ca/science/rpn/biblio/ddj/Web...

That link just shows a proposed third party IRQ config system for DOS, but wasn't actually shipped in Windows (in addition to the NT networking config).

Unbelievable. Often wondered how a prolog friendly os would feel..

The Rust compiler's semantic rules are being recast internally in a prolog style.

http://smallcultfollowing.com/babysteps/blog/2017/01/26/lowe...

>A third of all airline traffic is handled by systems that run SICStus Prolog

But are those systems responsible for all the I.T. problems that are plaguing the industry?[1] (I've been under the impression the issues were primarily with COBOL/mainframe systems, but wasn't aware Prolog was so widely used by airlines).

[1] https://www.google.com/search?hl=en&q=airline%20computer%20f...

Yes Markus does know, and has sprinkled examples throughout the book! One need look no further than the first chapter to find them.

One that was new and interesting to me is that gerritcodereview (by Google) is written in Prolog.

https://gerrit.googlesource.com/gerrit/+/master/prolog/

It's written in Java but embeds prolog as a rules engine for deciding when a change may be submitted.

https://gerrit-review.googlesource.com/Documentation/prolog-...

I know that Negota Logic uses Prolog for the reasoning in their Legal Tech app (which is mainly written in Java). Since the app itself has a terrible user experience and looks like stuck in a ninties dystopia, there might be better examples.

Gerrit (the code review tool) uses Prolog internally

* https://gerrit.googlesource.com/prolog-cafe/

I think that reinforcement learning might be suitable in prolog. Do you have an opinion on that?

In general, my opinion regarding machine learning and, in fact, also other tasks, is that Prolog is no less suitable to implement or teach these approaches than - for example - Python, which is currently often used in these areas. Dedicated libraries for machine learning are available and can be written for Prolog as well as for any other language, and Prolog of course also lets you easily interact with other programs via pipes and sockets.

So, yes, I agree: Prolog may well be suitable for this! In practice, for statistics-based methods, the core logic will likely be carried out by dedicated hardware which you may have to program in its own language. Prolog may still play a part also with such approaches, for example to generate test cases and correctness certificates, and as a rule-based safety measure to prevent certain situations from happening.

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