Laid out a set of questions for the ISE team on the structure and co-occurrence restrictions surrounding some ISGML tags. Made further progress with the TEI-to-ISGML conversion:

• Wrote handlers for some of the styling and alignment tags which must (apparently) be implemented at the line level rather than at the higher levels where we would put them in @rendition in TEI. This handles a limited set of stuff right now, but ultimately will handle more.
• Fixed a bug with column and page break occurrences.
• Wrote an Oxygen ant transformation which runs the XSLT transformation, saves the results, and then runs MJ's XML-generation tool from the toolchain to generate ISE XML, and checks that for well-formedness.

The results show some nesting issues with columns right now, but I've just learned there's actually a Java validator for the ISGML directly, so I'll have to get hold of that.