2014-11-02 wenzelm 2014-11-02 modernized header;
2014-09-22 wenzelm 2014-09-22 discontinued old "xnum" token category; simplified Lexicon.read_num, Lexicon.read_float: no sign here; express ZF numerals via "num" with mixfix grammar; recovered printing of ZF numerals: "one" is abbreviation;
2014-08-21 haftmann 2014-08-21 integrated appendix theory into main theory; tuned ML
2012-08-22 wenzelm 2012-08-22 prefer ML_file over old uses;
2012-03-15 paulson 2012-03-15 replacing ":" by "\<in>"
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
2011-12-01 wenzelm 2011-12-01 renamed inner syntax categories "num" to "num_token" and "xnum" to "xnum_token";
2010-02-13 wenzelm 2010-02-13 modernized structures;
2010-02-11 wenzelm 2010-02-11 numeral syntax: clarify parse trees vs. actual terms; modernized translations; formal markup of @{syntax_const} and @{const_syntax};
2009-10-17 wenzelm 2009-10-17 eliminated hard tabulators, guessing at each author's individual tab-width; tuned headers;
2008-03-01 wenzelm 2008-03-01 tuned ML code, more antiquotations;
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).
2007-10-07 wenzelm 2007-10-07 modernized specifications; removed legacy ML bindings;
2007-05-31 wenzelm 2007-05-31 moved Integ files to canonical place;