public function resourceElementName()
	{
		if ( $this->isFactVar ) return "Fact Variable";
		else if ( $this->isGeneralVar ) return "General Variable";
		else if ( $this->isParameter ) return "Parameter";
		else if ( $this->var instanceof Tuple ) return "Tuple";
		else if ( $this->var instanceof Formula ) return "Formula";
		else if ( $this->var instanceof ValueAssertion ) return "ValueAssertion";
		else if ( $this->var instanceof ExistenceAssertion ) return "ExistenceAssertion";
		return false;
	}