src/HOL/BNF/README.html
2013-07-30 blanchet 2013-07-30 more (co)datatype documentation
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"