Delete unused files.
Initial commit.
1. Implement EV+MxD.
1. If the forest is fully-reduced, level should be part of key for cache in saturation.
1. Compute the distance function (EV+MDD) using saturation. Duplicate code should be cleaned in the future.
Implement constraint saturation with EV+MDD. It is used to compute the minimum EU witness.
Create a branch to support long as edge type in EVMDD.