url check starts_with number to avoid looping

Hello, Below is my iRule that redirects an incoming url to a versioned url, by using the verison number in the header. In order to avoid infinite looping I am looking for a way to check "uri does not start_with number". Can you please suggest a way to do that? when HTTP_REQUEST { if { [HTTP::host] eq "xservicesdev.abc.com" and \ [matchclass [HTTP::uri] starts_with $::xservicesuri] and \ [HTTP::header exists Authorization] and \ [HTTP::header exists Version] } { HTTP::redirect "http://[HTTP::host]/[HTTP::header Version][HTTP::uri]" } } This line - [matchclass [HTTP::uri] starts_with $::xservicesuri] checks if the uri starts with some specific service domains (xservicesuri is a list of those names) to avoid looping. But this will also require change to the iRule everytime I have new domains. In order to avoid this I would like to check for the uri to "not start with" a version, so something like - not [matchclass [HTTP::uri] starts_with [HTTP::header Version]] but that didnt work. I tried both below: not [matchclass [HTTP::uri] starts_with $::xservicesuri] [matchclass [HTTP::uri] not starts_with $::xservicesuri] Would appreciate any suggestions. Thank you.