

Possible simplification of RDF formal model

From: Desmond D'Souza <desmond-dsouza@austin.rr.com>
Date: Mon, 10 Jan 2000 02:06:32 -0600
Message-ID: <000d01bf5b41$9d5294a0$11101b18@austin.rr.com>
To: <ora.lassila@research.nokia.com>

In the RDF formal model, have you considered treating Literals as a subset of Resources? The string representation of that resource (some people confuse this for "the value") actually is the URI of the resource.

So everything is a resource (Object), referred to by its URI. And all properties are directed edges on this sea of objects. For example: 
  a.. The number 7 always existed as a unique individual, before any particular document referred to it. The string representation "7" is its URI. Its 2's compliment representation is an alternate way of referring to 7. (This does not fit the current syntactic definition of URI, but I'll ignore that here).
  b.. So, what useful properties does 7 have?
  c.. 7 + 1 is no more than the "next" property of 7 i.e. 8.  (or see 7 + N below).
  d.. 7 +  5 = 12 is done as follows:
    a.. The + property of 7 is another resource +_of_7
    b.. +_of_7 is a function that maps any number N to 7 + N. Using the triple notation:
    c.. (0   +_of_7   7)
    d.. (1   +_of_7   8)
    e.. (2   +_of_7   9) etc.
      a.. (A common functional programming technique)
  e.. All these are optimized away in practice e.g. 2's complement representation of 7 ("0111") is an efficiently encoded URI of 7 that exploits preknowledge of the encoded URI of 8 ("1000") ... so that to get the (URI of the) "next" property of 7, you do not have to lookup the "next" tag, but directly manipulate the URI of 7 itself to get the URI of 8.  
    a.. This is just a variation of what relative pathnames do: take prefix of current URL, append relative offset, viola! URL of result.
  f.. Based on the above, I think rdf:_1, rdf:_2, rdf:_3 etc. are just 1, 2, 3, ...
  g.. This might simplify dealing with other typical "value" types: dates, money, etc. They have special URI syntax, a special way of comparing normalized URIs, and of looking up propertis to determine other related URIs. Thus, the date (pointed to by) 12/12/2999 always existed; as did the amount (pointed to by) $7654321; and so on.
  h.. This seems to fit in with RDF schema as well.
We use this in a cleaner approach to object modeling with UML (which we call Catalysis). Everything is an object, including numbers, strings, etc. All properties are links between objects. And all operations simply create or delete links and objects, though some objects and links cannot be deleted.



Desmond D'Souza
Received on Monday, 10 January 2000 02:59:16 UTC
