Hi Monks,

I am new to perl. I am doing validation tool in sgml, i want to check nesting in section tags. if the sections are improperly nested then i need to raise the error message. The error message should be identified by the content in id value of sec element. For example

My input

<sec id="4.1">

<sec id="4.2">

</sec></sec>

output

<sec id="4.1"></sec>

<sec id="4.2"></sec>

whether it is possible to check the nesting of tags without using the modules. My friend is capable of using xml twigs, but he is saying that it is not possible to do for sgml using xml twigs