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Re: error in Semantics document

From: pat hayes <phayes@ai.uwf.edu>
Date: Fri, 7 Feb 2003 11:24:00 -0600
Message-Id: <p05111b00ba697b7d966b@[10.0.100.86]>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: w3c-rdfcore-wg@w3.org

>The following claim from RDF Semantics, Section 0.3, is incorrect:
>
>	In particular, any graph obtained by replacing all blank nodes by
>	new blank nodes not in the original graph is an instance of the
>	original and also, by inverting the mapping, has it as an
>	instance. By our convention, such isomorphic graphs are considered
>	to be identical.
>
>To see this consider the ``original'' graph
>
>	a:b c:d _:a .
>	a:b c:e _:b .
>
>and the ``new'' graph
>
>	a:b c:d _:c .
>	a:b c:e _:c .

The wording is careless and unclear.  The intent was that the blank 
nodes would be replaced one at a time or in a 1:1 fashion, ie as a 
re-naming.  I will find a better way to express this.

Pat

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Received on Friday, 7 February 2003 12:24:04 EST

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