`app/main.py:1598`'s `site_standing = float(sum(standing.values()))` is the
first argument of SAFETY-30's latching, site-stopping sign detector AND the
`commanded_w` handed to SAFETY-18's `looks_frozen()`. It was pinned by nothing.
Coverage only: not one byte of `app/` moves - the shipped `sum` is correct.
WHY THE SUITE COULD NOT SEE IT. `_sign_site`, the only N>=2 site fixture in the
repository, runs shares of about -2500 W EACH - every one individually over its
320 W gate - so sum, mean and max(key=abs) all agree on it. Its values happen to
be equal, and a check comparing two things that happen to be equal cannot see
the difference it names. MUTATION.md habit 4, ninth instance, inside the site
half of the card that names the rule in its own text. At N=1 it is arithmetic
rather than a fixture defect: sum == mean == max == the one share, identically.
THE FIXTURE (test_watchdog.py part 9). Two SIMULATED units rated 220 W and
280 W, both obeying exactly, inverted gain, house importing 2000 W: the site
commands -500 W against a +2500 W meter and NO SINGLE SHARE clears the shipped
300 W gate. Four candidate reductions, four distinct answers, one over the gate
- sum -500, mean -250, max(key=abs) -280, [0] -220 - asserted as a precondition.
The asymmetry is load-bearing, and the smaller unit is first so [0] stays
distinct from max(key=abs). Gate shipped; only the hold is shortened.
BOTH CONSUMERS. 9b drives the same discrimination at SAFETY-18's threshold: the
site rail is 0.95 x 500 = 475 W, so the sum rails it while 250, 280 and 220 do
not. Shipped: BLIND_FROZEN, floor 0 W. Under both surviving mutations: not blind
at all, no floor filed - the battery may keep importing through a quarter whose
billed average is unobservable. The open quarter is backfilled with the stuck
reading so the mutant cannot reach the same action by the coverage route and
mask the difference. 9c asserts the N=1 identity on a real one-inverter tree.
SAFETY-32 already closes `list(standing.values())[0]` structurally and this card
does not claim it. Its disclosed blind spot - semantics are invisible to a shape
pin, permanently - is why the mean and max(key=abs) needed a behavioural set.
AND THE SEARCH FOR THE NEXT SURVIVOR FOUND ONE. `float(self.target)` - the
arbiter's site target instead of the sum of what stands on the wire - is -11 B
and survives all 20 files on untouched release/1.0 @ f72c48d, because every
fixture that existed was built where the two are the same number. They separate
when a device's reported range is narrower than its max_w: the `device` claim is
filed per actuator and never bounds the site target. Closed here by a
counterfactual that asks for -500 W while -250 W stands.
10 mutations of that one line, each on a fresh full-repo copy mounted :ro,
purged by tools/mutation_run.sh, the edit re-read from disk and the byte delta
printed. Ledger and honest gaps in DECISIONS/SAFETY-38-site-standing-pin.md.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU
adminandClaude Opus 5
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