| Tue, 19 Oct 2010 11:51:05 +0000 | urbanc | added a file about the easy closure properties of regular sets (the difficult parts, like complement, are missing) | changeset | files |
| Thu, 07 Oct 2010 05:30:21 +0000 | wu | Add a test file, after testing, this file can be deleted. | changeset | files |