"Orthogonal expressivity" of Pellet and Prolog?

Found a very interesting quote:

"Both OWL-DL and function-free Horn rules are decidable fragments of first-order logic with interesting, yet orthogonal expressive power"Motik B, Sattler U, Studer R. Query Answering for OWL-DL with rules. Web Semantics: Science, Services and Agents on the World Wide Web. 2005;3(1):41-60. Available at:

"Horn rules", is what prolog builds upon (a prolog statement are horn rules, AFAIS), so maybe Prolog fits into the category of "function-free horn rules"? (Gotta try to figure that out), and OWL-DL is the W3C standard for expressive semantics, that reasoners like pellet (which is available in bioclipse build upon.

Idea: How to store Prolog rules in Bioclipse scripts

It just struck me a very simple way of storing prolog code inside Bioclipse scripts, avoiding the need for a separate file containing the Prolog code. This might be very useful when using prolog as a kind of "query language" somewhat analogous to how SPARQL is used.
(Update: Prolog in fact turns out to be more powerful than SPARQL in this regard, as shown by the observation in this blog post, that SPARQL doesn't support backtracking).

The idea would be to simply store the prolog code in Bioclipse JS variable, and create a special manager method that can write such prolog query-code containing variables to a temporary file in the workspace and then just telling Prolog to "consult" that file, thereby "feeding the prolog engine" with the logic to use, from inside Bioclipse scripts.

Very good Prolog intro

Fond a very good Prolog intro. (Should of course better have learned prolog long ago... but didn't find no course for it before, and it's only now that I start to have aconcrete use for it ... )

It made me for the first time understand the meaning of bagof/3 and setof/3, since they compare it towards the easier-to-understand findall/3.


Initial performance comparison: Pellet vs Prolog in Bioclipse

I started with some initial performance testing for RDF data, between pellet an prolog, which are now both available integrated in Bioclipse.

A usage strategy emerges

A strategy for how to work with the Bioclipse/JPL/Prolog/Blipkit combination I'm setting up, is becoming clear.

The main idea with Bioclipse, as well as with having a prolog engine available in it, is for flexible and "interactive" knitting together of knowledge. One of the main questions regarding how to use a Bioclipse/JPL/Prolog/Blipkit combination, has been where to put the bulk of knowledge integration/reasoning code? There would in principle be three options for that:

  1. Bioclipse (Javascript environment)
  2. The Blipkit-Prolog/Bioclipse integration plugin (Java code, a.k.a. "Manager methods")
  3. The prolog engine (As a prolog file)

Converting RDF predicates to Prolog convenience methods with RegEx

Using SWI-Prolog's semweb package, I had extracted all predicates in a RDF source, containing some 1 million triples, into the following list:

Nice intro to RDF in Prolog (by Pellet author)

I found a nice introduction to the use of RDF in Prolog (SWI-Prolog). It contains short primers for both RDF and Prolog, so it should be accessible to anyone with a minimal programming background:

Testing out querying Prolog from Bioclipse

My project has been more or less on hold for around a week because of exams and other stuff. Looking forward to getting some concrete things done now. While still reading up a bit on OWL, I've started taken the first steps of the prolog/blipkit integration with a simple method for querying a prolog on the form "subject, a predicate, and an object".

Accessing BLIPKIT from command line Java or Eclipse Plug-in in Ubuntu

For my own documentation I went ahead and summarized all the steps I had to take

  1. In order to start blipkit from java commandline, and
  2. In order to start blipkit from an Eclipse plugin.

Prolog plugin for Eclipse

As a side-note, this looks interesting (Googled up by Egon), a Prolog Eclipse Plugin:

Could be interesting to combine that, in the future, with the results of my current project. Worth thinking about at least.