[Mulgara-general] Unable to load a Krule file into Mulgara

[Ghazzaoui, Ramez (NIH/NLM/LHC) [C]]

Hi, 

I am having trouble loading a rather simple Krule into Mulgara. Below
are the details about what I am doing and what the error is. I wonder if
anyone here knows how to work around this problem. 
Thanks! 
-Ramez 


I created my model and loaded the triples successfully with this:
-----------------------------------------------------------------
create <rmi://localhost/server1#nida_1>;
load <file:/export/home/moradmin/mulgara/raw_triples/nida_triples.nt>
into <rmi://localhost/server1#nida_1>;


Now I am trying to create an entailed Krule model with these Commands 
(which worked in the past on other models, other rules): 
---------------------------------------------------------------------
create <rmi://localhost/server1#krm_nida_sameAs>;
create <rmi://localhost/server1#nida_1_ent_sameAs>;

load <file:/export/home/moradmin/mulgara/rules/krm_nida_sameAs.rdf>
into <rmi://localhost/server1#krm_nida_sameAs>;

apply <rmi://localhost/server1#krm_nida_sameAs>
to <rmi://localhost/server1#nida_1>
   <rmi://localhost/server1#nida_1_ent_sameAs>;


I get this error: 
-----------------

2008-03-21 11:00:04,233 ERROR KruleLoader - 
   Unexpected error during loading: null
java.lang.NullPointerException
   at
org.mulgara.krule.KruleLoader.getConstraints(KruleLoader.java:1003)
   at
org.mulgara.krule.KruleLoader.getConstraints(KruleLoader.java:1014)
   at org.mulgara.krule.KruleLoader.loadJoinConstraints
       (KruleLoader.java:863)
   at org.mulgara.krule.KruleLoader.loadRdfObjects(KruleLoader.java:317)
   at org.mulgara.krule.KruleLoader.readRules(KruleLoader.java:254)
   at org.mulgara.resolver.DatabaseSession.buildRules 
       (DatabaseSession.java:508)
   at org.mulgara.server.rmi.SessionWrapperRemoteSession.buildRules 
       (SessionWrapperRemoteSession.java:461)
   at sun.reflect.GeneratedMethodAccessor19.invoke(Unknown Source)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke 
       (DelegatingMethodAccessorImpl.java:25)
   at java.lang.reflect.Method.invoke(Method.java:585)
   at
sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:294)
   at sun.rmi.transport.Transport$1.run(Transport.java:153)
   at java.security.AccessController.doPrivileged(Native Method)
   at sun.rmi.transport.Transport.serviceCall(Transport.java:149)
   at sun.rmi.transport.tcp.TCPTransport.handleMessages 
       (TCPTransport.java:460)
   at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run 
       (TCPTransport.java:701)
   at java.lang.Thread.run(Thread.java:595)
Syntax error (line 16): org.mulgara.rules.InitializerException: 
    Unexpected error loading rules


The Krule file (krm_nida_sameAs.rdf) is as follows: 
---------------------------------------------------

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE rdf:RDF [
<!ENTITY owl     "http://www.w3.org/2002/07/owl#">
<!ENTITY rdf     "http://www.w3.org/1999/02/22-rdf-syntax-ns#">
<!ENTITY rdfs    "http://www.w3.org/2000/01/rdf-schema#">
<!ENTITY xsd     "http://www.w3.org/2001/XMLSchema#">
<!ENTITY mulgara "http://mulgara.org/mulgara#">
<!ENTITY krule   "http://mulgara.org/owl/krule/#">
<!ENTITY bp      "http://www.biopax.org/release/biopax-level2.owl#">
]>

<rdf:RDF xmlns:rdf="&rdf;"
         xmlns:rdfs="&rdfs;"
         xmlns:owl="&owl;"
         xmlns:xsd="&xsd;"
         xmlns="&krule;"
         xmlns:krule="&krule;"
         xmlns:bp="&bp;"
         xml:base="http://mulgara.org/owl/krule/">

  <krule:URIReference rdf:about="#bp_short_name">
    <rdf:value rdf:resource="bp:SHORT-NAME"/>
  </krule:URIReference>

  <krule:URIReference rdf:about="#owl_sameAs">
    <rdf:value rdf:resource="owl:sameAs"/>
  </krule:URIReference>

  <Variable rdf:about="#name1">
    <name>name1</name>
  </Variable>

  <Variable rdf:about="#name2">
    <name>name2</name>
  </Variable>

  <Variable rdf:about="#value">
    <name>value</name>
  </Variable>

  <!-- * plain sameAs -->
  <krule:Rule rdf:about="#same_as">
    <hasQuery>
      <Query>
        <selectionVariables>
          <rdf:Seq>
            <rdf:li rdf:resource="#name1"/>
            <rdf:li rdf:resource="owl_sameAs"/>
            <rdf:li rdf:resource="#name2"/>
          </rdf:Seq>
        </selectionVariables>
        <hasWhereClause>
          <ConstraintConjunction>

            <argument>
              <SimpleConstraint>
                <hasSubject>
                  <Variable rdf:about="#name1"/>
                </hasSubject>
                <hasPredicate>
                  <URIReference rdf:about="#bp_short_name"/>
                </hasPredicate>
                <hasObject>
                  <Variable rdf:about="#value"/>
                </hasObject>
              </SimpleConstraint>
            </argument>

            <argument>
              <SimpleConstraint>
                <hasSubject>
                  <Variable rdf:about="#name2"/>
                </hasSubject>
                <hasPredicate>
                  <URIReference rdf:about="#bp_short_name"/>
                </hasPredicate>
                <hasObject>
                  <Variable rdf:about="#value"/>
                </hasObject>
              </SimpleConstraint>
            </argument>

            <argument>
            </argument>

          </ConstraintConjunction>
        </hasWhereClause>
      </Query>
    </hasQuery>
  </krule:Rule>

</rdf:RDF>