| Mon, 11 Jun 2018 18:05:43 +0200 | wenzelm | more abstract Export.Provider; | changeset | files |
| Mon, 11 Jun 2018 17:37:44 +0200 | wenzelm | clarified signature: persistent results; | changeset | files |
| Mon, 11 Jun 2018 15:50:28 +0200 | wenzelm | tuned signature; | changeset | files |
| Mon, 11 Jun 2018 20:45:51 +0200 | nipkow | tuned def. of del and proved preservation of rbt (finally) | changeset | files |