Slack Succession
Abstract
The succession relation for slack continuations gives the Catalan generating series.
Theorem 1.1 (Slack succession).
Lean statement: D5/S3/Combinatorics/LevelSequence/LevelSequenceSuccession.slack_succession
Proof. Machine-checked in Lean as D5/S3/Combinatorics/LevelSequence/LevelSequenceSuccession.slack_succession (✓ std3). ∎
Source. Repository-derived.
Acknowledgement. Toufik Mansour (2026). Wilf Classes for Level Sequences Avoiding Patterns of Length Three. DOI: 10.3390/math14111983. URL: https://www.mdpi.com/2227-7390/14/11/1983.
Commentary.
For a nonempty avoiding tail, the slack values of all admissible successors are obtained by the successive cuts determined by the tail and its initial spine.
References
- Truth anchor:
D5/S3/Combinatorics/LevelSequence/LevelSequenceSuccession.slack_succession - Dependency: D5/S3/Combinatorics/LevelSequence/LevelSequenceSlack
- Dependency: D5/S3/Combinatorics/LevelSequence/LevelSequenceWordCount