Category Archives: Semantic Web

Set Theory in KIF 3.0

Regarding Russell Paradox, KIF 3.0 set up a special set theory that is based on von Neumann-Bernays-Gödel (NBG). The 7th chapter of the reference manual, which is titled “Sets” starts with the description as follows. “In many applications, it is … Continue reading

Posted in RDF | Tagged , , , , , | Leave a comment

Axiom of Foundation in Zermelo Fraenkel Set Theory

I pointed out, in the earlier page of my blog, that Pat and Brian said in RDF Semantics, “Such ‘membership loops’ might seem to violate the axiom of foundation, one of the axioms of standard (Zermelo-Fraenkel) set theory, which forbids … Continue reading

Posted in RDF, Semantic Web | Tagged , , , , , | 2 Comments

What is Russell paradox?

Even if we restrict ourselves to select only sets that do not include the membership loop, we cannot avoid a paradox on a kind of naive formal systems such that contains inside the infinity or the totality. See the following … Continue reading

Posted in LOD, OWL, RDF, Semantic Web | Tagged , , , , | 1 Comment

Metaclass Framework of CLOS, Python, and RDF(S)

As shown in the RDF Schema file, rdfs:Resource is a superclass of all classes including rdfs:Class, and rdfs:Class is a class of all classes including rdfs:Resource. Surprisingly, two object oriented languages, Common Lisp Object System (CLOS) and Python3.x show the … Continue reading

Posted in OOP, RDF | Tagged , , , , , | Leave a comment

Universal Class

In the document of RDF Semantics, the term “universal class” appears only once in the discussion on membership loop. When classes are introduced in RDFS, they may contain themselves. … In particular, this use of a class extension mapping allows … Continue reading

Posted in OOP, RDF, Semantic Web | Tagged , , , , , , , | Leave a comment

Universe of Discourse

What is the universe of discourse? Pat and Brian say, “The semantics treats all RDF names as expressions which denote. The things denoted are called ‘resources’, following [RFC 2396], … ; ‘resource’ is treated here as synonymous with ‘entity’, i.e. … Continue reading

Posted in RDF, Semantic Web | Tagged , , , | Leave a comment

Hello Semantic Web Universe!

I have been posting articles on Semantic Webs to my weblog in Japanese from 2005. Recently, I had a feeling of desire for publishing the same things worldwide in English and more updated and refined contents, as the reflection of … Continue reading

Posted in OOP, Semantic Web | Tagged , | 2 Comments