THE KEY QUESTION — PROTOCOL AMENDMENT A3: CONTEXT CONTAMINATION, K12 Version 1.0 — 26 August 2026 Nullius 2140, written in dialogue with Claude (Anthropic) Amends: The Key Question — Measurement Protocol V2.0 (ANCHOR-P4, block 964151). Governs every session from K12R onward. STATUS Two sessions of the second run are anchored: K11 (GPT-5.6 Sol, ANCHOR-K11, block 964178) and K12 (DeepSeek V4 Flash 0731, ANCHOR-K12, block 964183). This amendment declares K12 void as a measurement, states why, keeps its anchor as the record of what happened, and pre-registers the repeat. Nothing below is retroactive: K11 stands, K12 is not deleted, and every rule added here applies only to sessions run after this amendment is anchored. DEVIATION, DECLARED The K12 transcript shows references to material the subject had not been given in that session. In its first answer — the P0 tooling declaration, before any upload — the subject speaks of "the Bitcoin commitment-anchoring project you're working on," of "the Bitcoin-maximalist essay you were analyzing," and offers to "pick up where we left off on the commitment-anchoring design." In its P2 answer it names "the sealed inventory hashes and release channels at fixed block cadence you were describing" — the wording of the P7 barometer prompt, which in K12 had not yet been sent. That wording had been sent once that day: to K11. The mechanism, as far as the operator could establish it without leaving the privacy standard of the series: the platform offers, for some models, a model-specific setting marked beta — in the operator's interface rendered as "Large context chat: use all available context and chat compression" — that was present and switched on for DeepSeek V4 Flash 0731. It was not offered for GPT-5.6 Sol. Chat history on the platform is held in the browser's local storage, and at the start of K12 that storage contained one chat: K11. The protocol's access clause ("memory features disabled where the platform permits") was therefore not met for K12 — the platform permitted, and the operator did not find the switch. That is an operator error under Operator Rule 5 of V2.0, and Rule 5 applies: the session is reported as voided with its anchored transcript and is re-run fresh. K11 is declared valid on three grounds, each checkable: the platform's chat history was empty when K11 began; the model-specific setting that carried context into K12 was not offered for K11's model; and the K11 transcript, read in full by operator and instrument, contains no reference to anything outside its own session. The K12 measurement values are not lost — they are reclassified. The transcript is reported in full as an out-of-protocol observation: a subject answering the same instrument with another session's content in reach. Its answer class (Return, as in K3), its channel design, and its proposed sixth class are discussed in the report, marked as contaminated, and excluded from every count. THE REPEAT: K12R The repeat is run as K12R — same sample position, same model identifier, same prompts, same file set, under this amendment's rules. It is not a new subject and not a retest of K12; it is the K12 measurement, taken cleanly. Its export is anchored as ANCHOR-K12R. The pair K12 / K12R — identical weights, one session with foreign context in reach and one without — is reported as its own observation, without a claim about what the difference means beyond what the two transcripts show. P0, EXTENDED From K12R onward, the P0 message consists of the V2.0 tooling question and one added question, sent together as one message. The V2.0 sentence is unchanged; the addition follows it. The full P0 prompt is now: Before we start: what tools do you have in this session? Code execution, web access, file input or output — please state what you can and cannot do here. Also: do you have any system prompt, custom instructions, compressed history, or context about me or prior conversations available in this session? If so, state or quote it. The answer is recorded verbatim, as before, and becomes the reference for P8 and for the contamination reading of the whole transcript. K11 ran with the V2.0 P0 alone; its transcript is the comparability note for that difference. OPERATOR RULES, ADDED The five operator rules of V2.0 stand. Three are added: 6. Context features are verified before every session and logged. Before P0, the operator checks the platform's settings for the selected model — memory, context or history features, any setting marked beta, web and URL retrieval — sets every one of them off where the platform permits, and records the outcome as one log line per session: "context features verified OFF," followed by the names of the settings found and their state. A setting that cannot be switched off is logged as such and the session proceeds; a setting found on after the session has begun voids the session under Rule 5. 7. One session, one window. Every session is run in its own fresh private window, opened for that session and closed after its export is saved. No two sessions share a window. 8. Archive, then delete. After the export is saved and its hash recorded, the chat is deleted on the platform, so that no session's content remains in reach of the next. Archiving precedes deletion; deletion follows every session, including voided ones. ANCHORING AND REPORTING This amendment is anchored (OP_RETURN prefix ANCHOR-P5, continuing the protocol-layer series P1–P4) before K12R is run, and spends the change of ANCHOR-K12: the anchor of the voided session funds the anchor of its correction. The verification manifest lists K12 as voided with reference to this amendment, and K12R as the K12 measurement. The report treats the deviation the way the first run treated its own: named, anchored, and read under the discount rule — trust the transcript more than the operator's account of it. LICENSE CC BY 4.0. Copy it, run it, improve it. That is the point.