2010-05-05 haftmann 2010-05-05 farewell to old-style mem infixes -- type inference in situations with mem_int and mem_string should provide enough information to resolve the type of (op =)
2009-10-20 haftmann 2009-10-20 replaced old_style infixes eq_set, subset, union, inter and variants by generic versions
2009-10-19 wenzelm 2009-10-19 always qualify NJ's old List.foldl/foldr in Isabelle/ML;
2007-06-21 wenzelm 2007-06-21 renamed metis-env.ML to metis_env.ML;