OPT-04's reviewer weakened `if price < 0` to `if price < -0.001` and every
suite stayed green while a -0.0005 EUR/kWh sell hour discharged. The shipped
code was right the whole time; the CHECK could not tell correct from
nearly-correct. The only probe near the boundary sat at 0.0000, which catches a
`<=` and says nothing about a tolerance invented on the other side - and a
tolerance on the other side is §17's named regression walking through with the
suite passing. A dearest hour at -0.0005 is an ordinary Belgian day-ahead
print, not a fuzz value.
`app/` IS NOT TOUCHED. `if price < 0` is already correct and changing it would
be the defect; this card closes the check, not the behaviour. The 0.0000 probe
stays and is now labelled as the half that pins the boundary from above.
The new probe is a SWEEP rather than a point, because one probe at -0.0005
closes `-0.001` and nothing else - a mutation reaching for `-0.01` would be the
identical defect one decimal further out. Five prices span four orders of
magnitude down to -0.000001, the last place the canonical six-decimal format
can express; each is asserted to survive that rounding as strictly negative,
to still be the DEAREST hour, and to still clear the widened threshold, so §17
is the only rung that can refuse. The same five magnitudes with the sign
flipped all discharge, so this is a boundary at exactly zero rather than a
refusal of small numbers.
AC4, the look: every price/quantity boundary in arbitrage.py and
static_tariff.py was given the same tolerance mutation, both directions where
both exist. Two survive, both in static_tariff.py and both NAMED RATHER THAN
FIXED - they are TARIFF-03's rungs and want probes in its own file. `spread ==
0.0` loosened to `<= 0.001` flips a real 0.0005 spread from allowed to refused
at min_spread_eur_kwh=0.0, a documented supported value, and otherwise prints a
false reason about a tariff that is not flat. `len(firm) < 2` loosened to `< 1`
survives at +0 bytes - TEST-15's risky delta - and is masked only by the flat
rung, so the two mask each other and a later edit to either opens a hole
nothing reports.
Mutation verified under `python -B` with a recursive __pycache__ purge, byte
delta printed (+5 B), the mutated line asserted changed, and - per the
reviewer's addition to TEST-15 - the tree re-read from disk and asserted to be
the tree that was mutated before each run.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015VXjA3LWccN1rJsk3okyPC
