[java] Exception in thread "main" org.hypergraphdb.HGException: org.hypergraphdb.HGException: java.lang.IllegalArgumentException
     [java]    at org.hypergraphdb.HyperGraph.open(HyperGraph.java:228)
     [java]    at org.hypergraphdb.HyperGraph.(HyperGraph.java:167)
     [java]    at org.hypergraphdb.HGEnvironment.get(HGEnvironment.java:51)
     [java]    at org.disco.Disco.initHGDB(Disco.java:87)
     [java]    at org.disco.Disco.init(Disco.java:68)
     [java]    at org.disco.Disco.main(Disco.java:36)
     [java] Caused by: org.hypergraphdb.HGException: java.lang.IllegalArgumentException
     [java]    at org.hypergraphdb.handle.PhantomHandle.storeRef(PhantomHandle.java:95)
     [java]    at org.hypergraphdb.cache.WeakRefAtomCache.atomRefresh(WeakRefAtomCache.java:250)
     [java]    at org.hypergraphdb.HyperGraph$9.call(HyperGraph.java:1882)
     [java]    at org.hypergraphdb.transaction.HGTransactionManager.transact(HGTransactionManager.java:206)
     [java]    at org.hypergraphdb.HyperGraph.replaceInternal(HyperGraph.java:1789)
     [java]    at org.hypergraphdb.HyperGraph.replace(HyperGraph.java:988)
     [java]    at org.hypergraphdb.HGTypeSystem.defineNewJavaTypeTransaction(HGTypeSystem.java:384)
     [java]    at org.hypergraphdb.HGTypeSystem.makeNewJavaType(HGTypeSystem.java:361)
     [java]    at org.hypergraphdb.HGTypeSystem$2.call(HGTypeSystem.java:343)
     [java]    at org.hypergraphdb.HGTypeSystem$2.call(HGTypeSystem.java:1)
     [java]    at org.hypergraphdb.transaction.HGTransactionManager.transact(HGTransactionManager.java:206)
     [java]    at org.hypergraphdb.HGTypeSystem.defineNewJavaType(HGTypeSystem.java:342)
     [java]    at org.hypergraphdb.HGTypeSystem.getTypeHandle(HGTypeSystem.java:751)
     [java]    at org.hypergraphdb.HGIndexManager.loadIndexers(HGIndexManager.java:99)
     [java]    at org.hypergraphdb.HyperGraph.open(HyperGraph.java:213)
     [java]    ...5 more
     [java] Caused by: java.lang.IllegalArgumentException
     [java]    at java.lang.reflect.Field.set(libgcj.so.81)
     [java]    at java.lang.reflect.Field.set(libgcj.so.81)
     [java]    at java.lang.reflect.Field.set(libgcj.so.81)
     [java]    at org.hypergraphdb.handle.PhantomHandle.storeRef(PhantomHandle.java:95)
     [java]    ...19 more

LEFT-WALL how did he do that ? 

Object (do[4], that[5])
Subject (do[4], he[3])
Tense (do[4], past_infinitive)
Number (that[5], uncountable)
Number (he[3], singular)
Quantification (he[3], Definite)


[head [name <>
       tense <>
       links [_subj [name <>
                     DEFINITE-FLAG <>
                     noun_number <>]
              _obj [name <>
                    noun_number <>]
              how [name <<_$qVar>>
                   TRUTH-QUERY-FLAG <>]]
       HYP <>]]


uncountable(that)[1]
past_infinitive(do)[1]
hyp(do)[1]
_obj(do, that)[1]
singular(he)[1]
definite(he)[1]
how(do, _$qVar)[1]
_subj(do, he)[1]
truth-query(_$qVar)[1]

should be .
how-query(_$qVar)[1]