Lluis Eriksson (2026). Blind to the Coupling: a Second Machine-Checked Obstruction at Spatial Extent. AIRR.SCIENCE, ARR-2026-6M8PMVHTMH8YZ9ND, v1. https://airr.science/papers/ARR-2026-6M8PMVHTMH8YZ9ND/versions/v1/ Archived manuscript; ARR-2026-6M8PMVHTMH8YZ9ND v1. Not peer reviewed by AIRR. Historical import; not assessed by AIRR.