Keyboard shortcuts

Press or to navigate between chapters

Press ? to show this help

Press Esc to hide this help

Prime Word Occupation Descent

Abstract

Prime-word history is not recoverable, and word actions descend exactly when commuting.

Theorem 1.1 (No prime-history reconstruction).

Proof. Machine-checked in Lean as D5/S3/Factorization/Combinatorics/PrimeWordOccupationDescent.no_prime_history_reconstruction (✓ std3). ∎

Source. Repository-derived.

Commentary.

Ordered prime histories are lists of Mathlib prime subtypes, while the occupation state is their canonical multiset quotient. The words [2,3] and [3,2] have the same occupation state but are distinct, so no section can recover every original word.

Theorem 1.2 (Order descent criterion).

Proof. Machine-checked in Lean as D5/S3/Factorization/Combinatorics/PrimeWordOccupationDescent.order_descent_criterion (✓ std3). ∎

Source. Repository-derived.

Commentary.

For arbitrary input and state types, U assigns a state update to each input. The public witness is a dynamics on input multisets whose value on every list occupation is the imported left-to-right runWord action.

Pairwise commutativity makes runWord invariant under list permutation and therefore defines the quotient dynamics. Conversely, applying any descended dynamics to the equal occupations of [p,q] and [q,p] forces the two updates to commute.

References