?
\d{1,32}on\d{1,32}, i want to make sure both numbers are equal, im new to regex and was confused by number of tokens, didn't find something useful for my case (\d{1,32})on\1 for a (not quite) regex engine supporting backreferences
(\d{1,32})on\1 for a (not quite) regex engine supporting backreferences 
<function name="f" params="x,y">
<block>
<var id="b"><intlit value="3"/></var>
<if>
<less>
<ref id="x"/>
<times>
<ref id="a"/>
<plus><ref id="b"/><intlit value="7"></plus>
</times>
</less>
<while>
<ref id="found"/>
<block>
<for var="i">
<range><intlit value="2"/><intlit value="5"/></range>
<print><ref id="i"/></print>
</for>
<if>
<eq><ref id="a"/><intlit value="2"/></eq>
<break/>
</if>
</block>
</while>
<assign>
<ref id="p"/>
<cos><intlit value="5"/></cos>
</assign>
</if>
<return><intlit value="5"/></return>
</block>
</function> 
