Improve IndependentConstraintSetUnion
#850
| Job | Run time |
|---|---|
| 15m 59s | |
| 17m 42s | |
| 12m 1s | |
| 15m 15s | |
| 5m 42s | |
| 18m 25s | |
| 10m 29s | |
| 17m 57s | |
| 39m 4s | |
| 16m 18s | |
| 41m 8s | |
| 51m 37s | |
| 51m 28s | |
| 52m 50s | |
| 18m 11s | |
| 43m 2s | |
| 15m 38s | |
| 17m 29s | |
| 20m 24s | |
| 14m 24s | |
| 8h 15m 3s |