Summing numbers with comma as decimal separator in XSLT?

Question

I have an XML file where the number are comma-separated

Answer 1

I feel like I say this a lot, but it bears repeating: the whole point of XML is that it provides data in an easily parsable form. XML that contains data that can't be parsed as XML makes no sense; if at all possible, you should either fix your XML or use a different format.