2016-12-18 wenzelm 2016-12-18 more standard notation (like infix);
2016-11-01 wenzelm 2016-11-01 tuned;
2016-11-01 wenzelm 2016-11-01 misc tuning and modernization;
2016-10-18 haftmann 2016-10-18 suitable logical type class for abs, sgn
2016-10-17 Simon Wimmer 2016-10-17 Modified transfer principle in HOL/NSA to cause less ho-unficiation
2016-10-16 haftmann 2016-10-16 more standardized theorem names for facts involving the div and mod identity
2016-09-26 haftmann 2016-09-26 syntactic type class for operation mod named after mod; simplified assumptions of type class semiring_div
2016-07-12 fleury 2016-07-12 sharing simp rules between ordered monoids and rings
2016-02-29 wenzelm 2016-02-29 clarified session; tuned headers;