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Re: local arity, term WFF-ness conflicts with merging requirement?

From: Adrian Paschke <adrian.paschke@biotec.tu-dresden.de>
Date: Sat, 31 May 2008 12:22:47 +0200
To: <public-rif-comments@w3.org>
Cc: <connolly@w3.org>
Message-Id: <20080531102236.7988A70000D7@mailserver.biotec.tu-dresden.de>
Hello Dan
 
In BLD, pred and funcs have one arity, and it is correct that the
restriction holds even across multiple documents. So the requirement is met
-- rulesets can be merged -- but if one ruleset is in error, then the merged
version will be able to detect the error.
 
- Adrian
 
 
From: Dan Connolly <connolly@w3.org
<mailto:connolly@w3.org?Subject=Re%3A%20local%20arity%2C%20term%20WFF-ness%2
0conflicts%20with%20merging%20requirement%3F&In-Reply-To=%253C1210016107.465
1.363.camel%40pav.lan%253E&References=%253C1210016107.4651.363.camel%40pav.l
an%253E> > 


Date: Mon, 05 May 2008 14:35:07 -0500


To: public-rif-comments@w3.org
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0WFF-ness%20conflicts%20with%20merging%20requirement%3F&In-Reply-To=%253C121
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Message-Id: <1210016107.4651.363.camel@pav.lan>
 
I noted these two bits of the RIF syntax:
 
"Each predicate and function symbol has precisely one arity"
 
"A well-formed term is one that occurs in a well-formed set of fomulas."
 
  -- http://www.w3.org/TR/rif-bld/
 
Those seem to be not web-wide definitions, but definitions
that just apply to one file or something. Otherwise,
to take an arbitrary example, the function symbol ABC:
what is its arity?
 
The context-sensitivity of those definitions seems
to conflict with the requirement to be able to
merge rule sets:
 
"4.2.12 Merge Rule Sets 
RIF should support the ability to merge rule sets. "
http://www.w3.org/2005/rules/wiki/UCR#Merge_Rule_Sets
 
If ABC has arity 2 in one rule set and arity 3 in
another, what happens when those rule sets are merged?
 
Is it worthwhile making the requirement more precise as follows?
 
  any collection of well-formed RIF formulas is itself well-formed
 
-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
gpg D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E

 
Received on Saturday, 31 May 2008 10:23:41 UTC

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