Lluis Eriksson (2026). Strict but Not Uniform: a Machine-Checked Spectral Gap at Every Finite Extent of the Coupled Slice. AIRR.SCIENCE, ARR-2026-1A608PTGTC9XX9JZ, v1. https://airr.science/papers/ARR-2026-1A608PTGTC9XX9JZ/versions/v1/ Archived manuscript; ARR-2026-1A608PTGTC9XX9JZ v1. Not peer reviewed by AIRR. Historical import; not assessed by AIRR.