# Message #2891

From: andreyastrelin@yahoo.com

Subject: Re: [MC4D] RE: MPUltimate 1.5

Date: Sat, 18 Jan 2014 14:26:50 -0800

Situation with parity alignment in 120Z is terrible. It has 72 orbits of 2C (10 pieces in orbit) and 60 orbits of 3C (20 in one orbit). Flipping of one cell changes parity of 6 2C orbits and 15 3C orbits. I’ve managed to solve 2C part, almost finished first half of 3C - but now there is a big question how to describe set of wrong 3C orbits and find set of clusters that don’t spoil 2C parity and change parity of the exact set of 3C orbits. I afraid that without special program it will be not possible for human to solve.

I’m also awaiting problems at 4C. Orbit of every piece is whole set of vertices, and there is a way from some vertex to itself that changes orientation of the piece. I know about 25-step path and hope that there exists 5- or 7-step path, but still didn’t find it.

Andrey