| Sat, 13 Apr 2019 08:43:33 +0000 | haftmann | backed out a93e6472ac9c, which does not bring anything substantial: division_ring is not commutative in multiplication but semidom_divide is | changeset | files |
| Sat, 13 Apr 2019 08:11:48 +0000 | haftmann | tuned | changeset | files |
| Sat, 13 Apr 2019 08:11:47 +0000 | haftmann | more document structure | changeset | files |