2013-07-15 traytel 2013-07-15 killed unused theorems
2013-05-25 haftmann 2013-05-25 weaker precendence of syntax for big intersection and union on sets
2013-05-07 traytel 2013-05-07 got rid of the set based relator---use (binary) predicate based relator instead
2012-09-21 blanchet 2012-09-21 clean up lemmas used for composition
2012-09-21 blanchet 2012-09-21 renamed "Codatatype" directory "BNF" (and corresponding session) -- this opens the door to no-nonsense session names like "HOL-BNF-LFP"