2014-11-02 wenzelm 2014-11-02 modernized header;
2014-08-21 haftmann 2014-08-21 integrated appendix theory into main theory; tuned ML
2013-04-10 wenzelm 2013-04-10 added ML antiquotation @{theory_context};
2012-03-17 paulson 2012-03-17 tidying and structured proofs
2012-03-06 paulson 2012-03-06 Using mathematical notation for <-> and cardinal arithmetic
2012-03-06 paulson 2012-03-06 mathematical symbols instead of ASCII
2011-11-20 wenzelm 2011-11-20 eliminated obsolete "standard";
2009-10-17 wenzelm 2009-10-17 eliminated hard tabulators, guessing at each author's individual tab-width; tuned headers;
2009-07-23 wenzelm 2009-07-23 renamed simpset_of to global_simpset_of, and local_simpset_of to simpset_of -- same for claset and clasimpset;
2008-02-11 krauss 2008-02-11 Made theory names in ZF disjoint from HOL theory names to allow loading both developments in a single session (but not merge them).