| Mon, 23 Mar 2015 19:05:14 +0100 | haftmann | explicit commutative additive inverse operation; | changeset | files |
| Mon, 23 Mar 2015 19:05:14 +0100 | haftmann | modernized | changeset | files |
| Wed, 25 Mar 2015 17:51:34 +0100 | blanchet | more multiset theorems | changeset | files |