*** empty log message ***
about to remove unwanted material to do with unit and pair.
archive.
archive.
archive.
ready for final proof-reading.
version for D-RisQ
archive.
added diagnostic checks on state change logging.
implemented new pragma command.
refactoring in preparation for more updates for article format 6.
archive.
archive.
archive.
first version which can read the OpenTheory base package.
defined OTSetFold to give hack-free coverage of the base package.
wip on reader; fixed missing implementation of log_subst_rule.
minor tidy-up.
Imported package: opentheory from RCS
Importing opentheory package: merge into top level