After yesterday's detailed discussion of how to handle transaction chains with nominal transactions in the spreadsheet generation, I started work on implementing it. The spreadsheet XSLT had grown by accretion and become horribly unmaintainable, so I've refactored and modularized it, added a function for detecting non-nominals, and bugfixed the results; I'm now ready to add the previous-non-nominal functionality, which should be fairly straightforward now.