alt text

Yeah, okay, at this stage we all know and love the Semantic Web Stack.

Against my better judgement, I find myself writing about it at the moment in the context of a little historical perspective for the Semantic Web.

But I'm stuck on the Proof bit. What was the original idea behind the Proof layer? My gut tells me that it was to do with the "oh yeah?" button that would be able to "prove" conclusions made by reasoners and so forth, but I've not been able to find anything concrete on the matter and Proof could well mean a lot of things.

Anyone have pointers to some material (or thoughts) about what the Proof layer is doing in there?

Maybe someone has seen the Proof layer lying about somewhere?

asked 26 Oct '12, 17:05

Signified's gravatar image

Signified ♦
accept rate: 37%

edited 26 Oct '12, 17:06


Did you lose it down the back of the sofa?

(26 Oct '12, 17:08) Rob Vesse ♦ Rob%20Vesse's gravatar image

Unless the layer is for remotely controlling the television, then no.

(26 Oct '12, 17:09) Signified ♦ Signified's gravatar image

So you know, at least, what the "Unifying Logic" layer is about? :-)

(26 Oct '12, 17:16) Michael Schn... ♦ Michael%20Schneider's gravatar image

Oh sure! I just asked it and it told me.

(26 Oct '12, 19:37) Signified ♦ Signified's gravatar image

Here is what TimBL has said about this in an old design issues document:


From what I read here and from what I think to remember from other statements that I heard/read, the idea was probably to use formal proofs in fully-automatic agent-based negotiation or access-request activities, where one client agent (on behalf of a human) proofs to some service agent that it is allowed to access some information, etc. So there would probably be some client-specific challenge, stated in the form of an assertion in logic (see the layer below), and the client agent would have to provide a formal proof for it, otherwise (for other clients without access), creating such a proof would be too hard computationally. As checking a proof is much easier than creating it (without clues), the service agent would be able to check whether the client agent has access rights or not (or whatever). Based on all of this is then - obviously - trust! :-)

Now, this all sounds a little odd today, and I haven't heard of such a logic/proof based method for access control in the last years, and this may mean that the proof part is perhaps not relevant anymore.

PS: I believe to remember that the classic Scientific American article as of 2001 included something about this agent-related stuff. EDIT: Signified's self-response provides a proof! :-)

permanent link

answered 26 Oct '12, 17:59

Michael%20Schneider's gravatar image

Michael Schn... ♦
accept rate: 34%

edited 02 Nov '12, 18:49

Thanks for that! I must check out that Sci.Am. article again anyways, but after the weekend.

(26 Oct '12, 21:11) Signified ♦ Signified's gravatar image

You can add this: http://www.w3.org/DesignIssues/RDFnot.html , and look for the word "proof".

(27 Oct '12, 05:47) Antoine Zimm... ♦ Antoine%20Zimmermann's gravatar image

For posterity, the relevant part of the Scientific American article is:

An important facet of agents' functioning will be the exchange of "proofs" written in the Semantic Web's unifying language (the language that expresses logical inferences made using rules and information such as those specified by ontologies). For example, suppose Ms. Cook's contact information has been located by an online service, and to your great surprise it places her in Johannesburg. Naturally, you want to check this, so your computer asks the service for a proof of its answer, which it promptly provides by translating its internal reasoning into the Semantic Web's unifying language. An inference engine in your computer readily verifies that this Ms. Cook indeed matches the one you were seeking, and it can show you the relevant Web pages if you still have doubts. Although they are still far from plumbing the depths of the Semantic Web's potential, some programs can already exchange proofs in this way, using the current preliminary versions of the unifying language.

permanent link

answered 02 Nov '12, 16:28

Signified's gravatar image

Signified ♦
accept rate: 37%

edited 02 Nov '12, 16:28

Your answer
toggle preview

Follow this question

By Email:

Once you sign in you will be able to subscribe for any updates here



Answers and Comments

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text](http://url.com/ "title")
  • image?![alt text](/path/img.jpg "title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported

Question tags:


question asked: 26 Oct '12, 17:05

question was seen: 2,932 times

last updated: 02 Nov '12, 18:49