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Re: [GRAPHS] g-box - abstraction or concrete?

From: Ivan Herman <ivan@w3.org>
Date: Sun, 27 Feb 2011 10:32:26 +0100
Cc: public-rdf-wg WG <public-rdf-wg@w3.org>, Sandro Hawke <sandro@w3.org>, Pat Hayes <phayes@ihmc.us>
Message-Id: <DDA7F3D8-B67B-4C17-9640-F1C43F1A3A83@w3.org>
To: nathan@webr3.org

On Feb 25, 2011, at 21:48 , Nathan wrote:
> a g-box is a container of statements which form a particular view of a subset of the universe of discourse, the container is stateful such that it (potentially) contains different statements over time, at any one time the statements in the container form a set which can be considered the current state of that container (g-snap) and they form a current view of a the particular subset of the universe of discourse which they describe.
> A g-box is a stateful abstraction whose state is managed by an abstract protocol, the abstract protocol is realized via various machine protocols which manage the state of the g-box via messages and pass full or partial representations of the current state (g-snap) in various lexical forms (g-texts).
> A g-box can be given a name, and when a g-box is given a name the name becomes a namespace since the g-box is a container, and this namespace serves as the scope for all things within the g-box (statements/names/nodes). Thus a named-g-box becomes an Aristotelian abstraction where the current state of that named-g-box forms a particular scoped view of subset of the universe of discourse.
> Since a g-box is an abstraction, it cannot be duplicated or replicated (I'm tempted to say a g-box is a Platonic abstraction and a named g-box is an Aristotelian abstraction), however two g-box's can share the same name(s) and machine protocols can be used to try and synchronize the current state of the g-box's sharing the same name such that they all offer the same view of the subset of the universe of discourse which they describe. This process can be seen as forking a g-box at it's current state to create a new g-box with the same current-state (g-snap), then pulling/pushing changes to the state in order to keep them aligned and sharing the same view / saying the same thing.
> make sense?

Hm. That is not exactly the way I understood things although it may not be so far off after all... I just try to extrapolate.

Going back a bit to the root of the discussions, ie, Pat's mail:-): he talks about abstract graphs which, in my mind, is the same as Sandro's g-snaps. These are mathematical abstractions, ie, sets, which never exist in the real world. If you want to go back to the Greek world (and I am not ashamed to say that I may be wrong in my understanding of the greek philosophers), in my mind a g-snap is an ideal, a Platonic abstraction. And a g-text is a textual description of a g-snap.

A g-box is a shadow of a g-snap in Plato's cave allegory; a concrete, tangible representation of a g-snap. Well, it is a little bit smarter because when poked, it can give you some sort of a representation of a g-snap (eg, in the form of a g-text). But no, for me a g-box is not an abstraction, it is a real thing somewhere. Because it is a real thing, it can have a name, and two g-boxes are different things even if they represent the same g-snaps.

Trying to use the terminology... if I have something like

{ <a> <b> <c> }

in SPARQL (or n3), what is it? Is it a particular g-text representing a g-snap? Probably...

if I describe a rule (I use N3 syntax here because it is simpler than RIF would be, but that is just syntax):

{ ?a <b> <c> } => { <e> <f> ?a }

what does it mean in our terminology? Both sides describe a pattern for a family of g-snaps. Would one say that

"If a g-box's g-snap matches the rule's left hand side, then extend the g-box's g-snap to include the right hand side"? 

(I am sure that I am just driving our logicians up the wall with this statement...).

But then... do I have (do I need?) a syntax saying: "this particular g-box's g-snap should be a superset of this particular g-snap"? SPARQL has a syntax of the form

GRAPH <URI> { graph pattern... }

but we have to be careful with the analogy with a query language...

O.k., probably time to stop...


Ivan Herman, W3C Semantic Web Activity Lead
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Received on Sunday, 27 February 2011 09:31:08 GMT

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