Is this a legal expression?

<xsl:variable name="teststring" 
				expr="
					customer_id[contains(.,$_id)] and
	
company_name[starts-with(.,$_company)] and 
	
contact_name[starts-with(.,$_contact)] and 
	
contact_title[starts-with(.,$_title)] and 
					address[contains(.,$_address)] and 
					city[starts-with(.,$_city)] and 
					region[starts-with(.,$_region)] and 
					postal_code[contains(.,$_postal)]
and 
					country[contains(.,$_country)] and 
					phone[starts-with(.,$_phone)] and 
					fax[starts-with(.,$_fax)]
				"/>


<xsl:if test="$teststring=true">


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