2026-01-27

I found a library SoPlex that allows you to solve an LP one iteration at a time, capturing the intermediate BFS’. I created a small non-tu OHCP instance and recorded the BFS after each iteration. All of them were integral. The solver didn’t set any $x_i^{+},x_i^{-}$ as a basic variable until iteration #1586 (1867 iterations total).

The complex is a cubicial complex of a cube, with a hole.

Since they were all integral, I rendered each iteration ($y$ and $x$ chains) and created an animation: