<xsl:variable name="BaseRDFURL" select="concat($getterURL,'getxml?uri=helm:rdf:www.cs.unibo.it/helm/rdf/')"/>
<xsl:variable name="BaseRDFURLForward" select="concat($BaseRDFURL,'forward//')"/>
<xsl:variable name="BaseRDFURLBackward" select="concat($BaseRDFURL,'backward//')"/>
<xsl:variable name="BaseRDFURL" select="concat($getterURL,'getxml?uri=helm:rdf:www.cs.unibo.it/helm/rdf/')"/>
<xsl:variable name="BaseRDFURLForward" select="concat($BaseRDFURL,'forward//')"/>
<xsl:variable name="BaseRDFURLBackward" select="concat($BaseRDFURL,'backward//')"/>