# LIB2-261 — Retired independent-channel source doorway

- class: RETIRED · review_state: PUBLISHED · house_tier: not yet assigned
- labels as printed: math_status None · attachment None · scorecard tier word none (PDF p.None)
- basis: {"pdf_sha256_prefix": "b64ddcd9e16a6dcd", "release": "Rev33.1_S369"}

## Statement

The earlier source model treated the two channel patterns as independent rather than as the images of one common selector contrast.

## Caution

The paired-source replacement does not select the common contrast or remove the separate arrow-selection problem.

## Primary source

Appendix S, §4, Paired-source replacement, PDF p.304: "The correct source model (correcting the retired house doorway, casualty #4) is a single common selector contrast, not independent channel patterns."

## Machine

- url: /library-v2/LIB2-261/
- content_sha256: d3fe2d5466c78461c180a2a09f059c0fdad10912dcadc6b64be1cee230c5c749
- candidate_ids: C2-105

## Freshness

- BUILD_STAMP S371a · 2026-09-26T22:53Z · master 01d1a5873ede42f5 · cut 9dcc6ce9a8ee3e02
- Declared volatile fields (R36): BUILD_STAMP