R12 RGDE v1.1 Causal-Control Mechanics Amendment

Status: frozen after positive-arm evaluation and before any replacement control score. No model is refit by this amendment.

Defect

Jobs 693118--693121 completed cleanly, but inspection of the preregistered row-rotation intervention exposed a scorer defect. The factorized development file is organized in four-surface semantic quartets and make_batches also forms small length buckets. Rotating one row inside a batch therefore often selected another surface with the same operation program or query position. The old intervention_rows counter measured a changed row index, not a changed semantic field.

The original development_predicted_shuffled.json and development_query_shuffled.json are retained as mechanical diagnostics but are inadmissible for gates 7--8. The treatment, gold, untied, and composed-arm scores are unaffected. No weights, packet, targets, positive evaluator, data, seed, or advancement threshold changes.

Frozen repair

The evaluator constructs one deterministic global permutation before batch inference. It groups rows by the declared intervention key, rotates the sorted groups by the largest group size, and asserts that every destination key differs from its source key. For operation intervention the key is the complete two-operation structured program. For query intervention it is the requested position. It then compiles destination and source rows independently and replaces only the bounded operation tuple or query vector.

On all 2,048 development rows, both global permutations are bijections and all 2,048 semantic keys differ. Structured keys select a causal control source only; no gold state, transition, or answer enters the executor.

The replacement control job uses the already frozen tied executor state d31fd3e6150dd352cd0eea5063f960393e9017ac3ab729b5c536fd1f1c432184. It writes new filenames and refuses overwrite. It does not train or modify any parameter.

Frozen source SHA-256 values are:

Fifteen focused CPU tests, a full 2,048-row derangement audit for each key, Ruff, py_compile, shell syntax, and git diff --check pass.