The Pair before the Terminal Configuration
Abstract
Avoidance and a cyclic successor determine two additional suffix entries.
Theorem 1.1 (Two forced suffix entries).
Lean statement: D5/S3/Combinatorics/FundamentalBijection/ThetaCube312Suffix.terminal_pair_positions
Proof. Machine-checked in Lean as D5/S3/Combinatorics/FundamentalBijection/ThetaCube312Suffix.terminal_pair_positions (✓ std3). ∎
Source. Repository-derived.
Acknowledgement. Kassie Archer, Robert P. Laudone (2024). Pattern avoidance and the fundamental bijection. DOI: 10.48550/arXiv.2407.06338. URL: https://arxiv.org/abs/2407.06338v1.
Commentary.
For a 312-avoiding permutation of size n at least seven ending with n minus one, two, n, one and having cyclic successor n minus three for the letter three, the entries at positions n minus six and n minus five are three and n minus two.
References
- Truth anchor:
D5/S3/Combinatorics/FundamentalBijection/ThetaCube312Suffix.terminal_pair_positions - Dependency: D5/S3/Combinatorics/FundamentalBijection/ThetaCube312Edge