| Sat, 12 May 2012 20:54:00 +0100 | Christian Urban | added a lemma about composition and permutations | file | diff | annotate |
| Wed, 04 Apr 2012 06:19:38 +0100 | Christian Urban | updated to Isabelle version April 1 | file | diff | annotate |
| Fri, 30 Mar 2012 13:56:36 +0200 | Cezary Kaliszyk | Clean the proof of Aux | file | diff | annotate |