[Om] Going real with the OpenMath CD Linked Data

Christoph LANGE ch.lange at jacobs-university.de
Wed Jul 27 12:21:41 CEST 2011


Hi Paul,

I tried to fix the problem and the RDF generation should work now.
Details below.

On 27/07/2011 01:46, Paul Libbrecht wrote:
> Are you using externals? This client is still at version 1.0.8 !! It
> probably does not support that.
> I removed that https directory and I let you check in inside here the
> real files.

Oops, sorry, i didn't know. I have now recreated krextor-xslt as a
static copy of the required files (using "svn export"). BTW note that,
with or without using externals here, there is a slight redundancy.
Krextor itself relies on some of the OpenMath XSLTs for doing its job.
However, I won't be able to integrate Krextor into the OpenMath SVN
more seamlessly, as Krextor is a generic library that is also used for
other purposes (such as extracting RDF from OMDoc, where some OpenMath
functionality is also required).  But I think that's not really a
problem.  Any potential inconsistencies can be accommodated by keeping
the krextor-xslt directory up to date, and it's in my best interest to
take care of that.

> I tried checking out libraries/krextor, then adjusted the xslt path into
> build the xml to:
> libraries/krextor/src/xslt/transform-ocd..rdf-xml.xsl
> but I still got an XSLT error below.

Thanks for reporting; I will comment below.

> PS: would you like to have ssh access on there? It should be
> negotiatable.

It's reasonable that I should be responsible for making sure that the
RDF generation works, so indeed it would make sense if I had ssh
access.  How would I obtain it?

> [xslt] Loading stylesheet
> /export/www/webroot/openmath.org/svn.openmath.org/www/libraries/krextor/src/xslt/transform-ocd..rdf-xml.xsl
> [xslt]
> /export/www/webroot/openmath.org/svn.openmath.org/www/libraries/krextor/src/xslt/extract/util/openmath.xsl:34:46:
> Fatal Error! java.io.FileNotFoundException:
> /export/www/webroot/openmath.org/svn.openmath.org/www/libraries/krextor/src/xslt/extract/util/openmath/om2cmml.xsl

These are the OpenMath externals that Krextor uses, which I mentioned
above.  Maybe it was not checked out completely.

> [xslt]
> /export/www/webroot/openmath.org/svn.openmath.org/www/libraries/krextor/src/xslt/extract/ocd.xsl:308:96:
> Fatal Error! XPath syntax error at char 47 on line 308 in
> {...cdbase-or-default(../@cdbas...}:
> [xslt] Cannot find a matching 1-argument function named
> {http://www.openmath.org/OpenMath}cdbase-or-default()

The XSLT module that declares this function and related once is
actually part of the Krextor core (extract/util/openmath.xsl), but
maybe Saxon failed to compile that XSLT, as it imports the
above-mentioned ones from the OpenMath SVN.

I just tried successfully (from the www directory):

$ java -jar libraries/saxon/saxon9he.jar cdfiles2/cd/alg1.ocd 
libraries/krextor-xslt/transform-ocd..rdf-xml.xsl 2> /dev/null | head -n 2
<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"

Indeed, if I delete the "extract/util/openmath/" directory (which
comes from the OpenMath external), I can reproduce exactly the error
you got.

BTW Saxon gives you a lot of warnings due to multiple imports of some
"fxsl" XSLTs.  That is not a problem, and it can be ignored.  It is
due to the inherent modularity of Krextor.  In the long run I hope to
get rid of the FXSL library, as XSLT 3.0 will natively support those
functional-programming constructs for which I'm using FXSL.

Cheers,

Christoph

-- 
Christoph Lange, Jacobs University Bremen
http://kwarc.info/clange, Skype duke4701

Workshop: Ontologies come of Age in the Semantic Web (OCAS)
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