Post #3121063

@sol_hsa@mastodon.gamedev.place I wonder if ✨maths✨ (algebra in particular) rather than brute force can answer these questions. I remember similar puzzles being proven impossible by calculating a parity bit from the puzzle state, in such a way that the value remained constant when a valid move is made. The converse might be harder. Also, if you can prove that a particular state is reachable from any start state, and moves are reversible, then any state is reachable from any other.