Duplicated-fact drift is the fourth error class and the only one with no
executable rule. No positive control catches it (both copies are
internally consistent) and re-derivation does not either (the copy
reproduces whatever it was copied from). It is caught only by reading a
copy against its source, which nothing in the loop required.
facts.toml holds 15 facts and is GENERATED by `make facts-gen` from
cb-cost, dep-weight and rule-coverage. The trap this task named — a
hand-maintained registry that becomes another drifting copy — is closed
by facts-check re-running the instruments and failing when the committed
registry disagrees with them. A stale registry cannot certify stale
artifacts.
An artifact quoting a fact tags it: **$93.15** <!-- fact --> with the key.
17 occurrences across 5 artifacts are now checked.
Falsified before being believed: changing CostAccounting.md line 158 from
$93.15 to $92.87 — the exact historical drift — produced exit 1 naming
the file, the line and the expected value. Tested against the class it
exists to catch, on a real artifact, not only in its self-test.
It then caught a live tag inside its own documentation example in
InnerLoop.md within the hour. Third time a gate has failed on its own
pass's work.
What it does not close is stated rather than implied: 22 untagged literal
copies remain and are reported, not failed. Tagging is opt-in, a number
can legitimately recur, and a gate that fires on coincidence gets routed
around. Naming the uncovered surface beats claiming the class is closed.
InnerLoop single-source-of-fact moves from prose to executable — v1.3.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The price sheet had two defects of one shape -- a schema that could not
hold the fact it needed, the same criticism the cost survey levelled at
the State Hub.
CA-16 time-boxed rates are DATA. Sonnet's intro price lived in a
`# intro ...` comment and was invisible to the collector that
reads the file. Now promo_input/promo_output/promo_until,
applied per response at its own timestamp.
CA-17 the 90-day staleness rule was prose in MetricsAndScenarios 1a
that every M-D2-CST verdict silently inherited. Now `recorded`
+ `max_age_days` in the sheet, and a stale sheet ABORTS.
Both are exercised by make cost-test: the promo rate must apply before
2026-08-31 and lapse after, and a 102-day-old sheet must trip.
Applying CA-16 moved AC-1 from $93.32 to $93.15 -- the $0.17 CB-EV-0002
predicted, now collected rather than noted. That is a legitimate
retarget under T07's distinction: the instrument disproved the target,
and its output is in this commit. The number has now been stated five
times ($248.46, $92.21, $92.87, $93.32, $93.15), each correction from a
different mechanism.
Evidence tables regenerated from the tool rather than hand-patched,
per CA-15 -- which is the rule that exists because hand-typed tables
were the only thing the adversarial review found wrong.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
AC-1 $93.32 ($92.21 main + $1.11 subagent), residual $0.000000. No
unmeasured rows. Composition: 88.0% cache, 11.9% output, 249:1 context
re-read to text written.
The question that could not be answered before: what /compact costs.
The transcript records it directly — 542,991 -> 19,974 tokens, a 27x
reduction. Cost per turn fell from $0.457 (136 turns before) to $0.149
(202 turns after). The 202 post-compact turns cost less than half the
136 before them.
This qualifies CB-WP-0003 T04: sessions are bounded-quadratic, not
quadratic. Cost grows with context between compactions and resets at
each one, so the failure mode is a long UNCOMPACTED session. Whether a
fresh session beats a compaction is now measurable, and T04 should
measure it before prescribing one task per session.
Stale $0.66/$92.87 targets updated across survey and workplan.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
