Sure. Change the sub to:

sub subst {
    my ($twig, $value) = @_;

    $value->subs_text ('^s$', 'x');
    $value->print ();
}

[download]

I can thoroughly recommend the XML::Twig documentation by the way. It is long, but there are some really good examples.

True laziness is hard work

In reply to Re^3: Replace MathML content using Twig by GrandFather
in thread Replace MathML content using Twig by renovatio

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