xmlcalabash extensions step: No 'class' in configuration for cx:mathml-to-svg

Hello,

this is probably a silly question. I would like to use 2 xmlcalabash
extensions step with the docbook xslt20 stylesheets: mathml-to-svg and
xslthl, and I would like to do that in my own Java program.

So far, I have working Java db5 -> html conversion code (using saxon-he
and [email protected]). But when I try to use the cx:mathml-to-svg I
get the following error message:

> DefaultXProcMessageListener - Misconfigured. No 'class' in
> configuration for cx:mathml-to-svg

I guess that I haven't understood how the Java class of the extension
step is registered with xmlcalash. On the class, there is an annotation

> @XMLCalabash(
>         name = "cx:mathml-to-svg",
>         type = "{http://xmlcalabash.com/ns/extensions}mathml-to-svg")
and there is an (extra) library.xpl.

Perhaps somebody could explain me the about the relation of the 2 files
- and what have to been done to register an extension step with
xmlcalabash successfully.

Kind regards,

Thomas