Skelet 10
1LC0LA_---0LC_0RD1LA_1LB1RE_1RD0RE (bbch), called Skelet #10, was one of Skelet's 43 holdouts and one of the last holdouts in BB(5). It is a double fibonacci counter.
Behavior
Skelet 10 implements two base fibonacci counters, one on the right tape side and one on the left tape side. The TM halts if these counters become desynchronised.[1] The right side counter can be described by the following rules:[2]
A> 0 10^k 0 --> <D 0^2k 10 B> 10 10^k 0 --> <D 0^2k+1 10
The left side counter encodes base fibonacci differently and is also reversed, with the least-significant digit being on the right.[2]
References
- ↑ https://arxiv.org/pdf/2509.12337 Determination of the fifth Busy Beaver value
- ↑ 2.0 2.1 https://www.sligocki.com/2023/03/14/skelet-10.html