Thanks Matt! There were a bunch of other problems after that, but I managed to solve them all, and by all appearances I've successfully updated the extension for build 6G60. Interested parties can find it here
. I'm going to play around with it, and if it works just fine then I'll submit the update to the inform7 website.
EDIT: more specifically, I've defined the number variables that were previously only defined in 'let x be y' statements, got rid of the redundancies in statements like 'increment x by one', and changed 'not a verb I recognise' to 'the not a verb I recognise error'.