| Comparator | Description |
| SmallestDomainFloat | selects floating point variable with the smallest domain size |
| LargestDomainFloat | selects floating point variable with the largest domain size |
| LargestMinFloat | selects floating point variable with the largest min value |
| LargestMaxFloat | selects floating point variable with the largest max value |
| SmallestMinFloat | selects floating point variable with the smallest min value |
| SmallestMaxFloat | selects floating point variable with the smallest max value |
| WeightedDegreeFloat | selects floating point variable with |
| the highest weight divided by its size | |
| MostConstrainedStatic | selects set variable which has most constraints assign to it |
| MostConstrainedDynamic | selects set variable which has the most pending constraints assign to it |