Counterexample · noncommutative receipt

QA-HUR-FIB-X02

Order changes the second-layer receipt

Exact statement

Two noncommuting first-layer corrections can have the same affine sum but different ordered second-layer products.

StatusProved and reproduced
External reviewNo documented external or specialist review of this Quotient Arsenal result is recorded.

Context

Finite quotient words do not lift one factor at a time independently. Local affine lift fibres must be transported through the ordered product; the target defect then lives in a product-image cokernel that is invariant under quotient Hurwitz moves.

Proof or evidence

The elementary matrices satisfy e12e21=e11e_{12}e_{21}=e_{11} while e21e12=e22e_{21}e_{12}=e_{22}.

Verification notes

The exact written argument and available certificate were inspected; the public maturity level reflects whether import-time replay was complete.

Limitations

  • No novelty or specialist-review claim is made; the statement is limited to the displayed presentation and hypotheses.

Open work

Never replace ordered cross terms by an unordered quadratic count.