SAFETY-86: peak guard outranks the maintenance hold

During a HOLD the holding battery gives what keeps the quarter at the peak
aim. N=1: the peak floor is refiled at P_MAINTENANCE, as for a drain
(SAFETY-83). N>=2: the hold's pin is raised to the floor minus what the
other live batteries may place, so they give first. A site stop still
decides alone. The hold ends on its clock even if the level dipped.
Below the aim nothing changes (rows identical).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

goodwe_controller/DECISIONS/SAFETY-83-peak-over-drain.md

@@ -30,6 +30,5 @@ everything. Where the floor is at or below the drain rate nothing changes.
 **Not changed.**
 - Between the drain rate and the peak aim, the house still imports what the
   drain leaves (N=1 behaviour kept by the identity). At N=2 the loop covers it.
-- A maintenance HOLD (0 W, 120 min, battery full) still outranks the peak
-  guard at N=1. Discharging there spends the charge the BMS balances on; it is
-  an owner question, not this fix.
+- A maintenance HOLD (0 W, 120 min, battery full) still outranked the peak
+  guard at N=1. Fixed by [[SAFETY-86]].

goodwe_controller/DECISIONS/SAFETY-84-charge-at-two.md

@@ -41,6 +41,6 @@ was fine.
   and the battery gives until the quarter is safe. The same sizing would fit
   there; that is an owner question, not this fix.
 - Outside a cheap window (`hi = 0`, solar only) nothing is filed, at any N.
-- A HOLD (SAFETY-86) and the "Battery is not keeping up" alarm (SAFETY-85)
-  are untouched. In the identity runs that alarm's log line comes as often at
-  N=2 as at N=1 (2 in 480 cycles).
+- A HOLD (later fixed by [[SAFETY-86]]) and the "Battery is not keeping up"
+  alarm (SAFETY-85) are untouched. In the identity runs that alarm's log line
+  comes as often at N=2 as at N=1 (2 in 480 cycles).

goodwe_controller/DECISIONS/SAFETY-86-peak-over-hold.md

@@ -0,0 +1,46 @@
+# SAFETY-86 - the peak guard outranks the maintenance HOLD
+
+**Status: DECIDED 2026-09-30 (owner).** Follows SAFETY-83's "Not changed"
+list. Tests: `test_safety86.py`.
+
+**The defect.** The HOLD (battery resting full after the maintenance charge)
+is a SET of 0 W at `P_MAINTENANCE` (60), above the peak floor (`P_PEAK`, 50),
+so the floor did not bind. At N=1 a 6500 W house banked 6500 W quarters and
+'Load too high' fired (SAFETY-83 rig test, check 4). At N=2 only the other
+battery gave: 4500 W against a 3950 W aim (SAFETY-84 rig test, check 6).
+
+**The fix** (`main.py`, `_peak_over_hold()`).
+- N=1: during a HOLD a peak floor above 0 W is refiled at `P_MAINTENANCE`, as
+  for a drain (SAFETY-83). The battery gives the floor; the Why reads "raised
+  for the peak limit".
+- N>=2: the holding battery's pin is raised to the floor minus what the other
+  live batteries may place (their hard `hi`, or their pin). The others give
+  first, the holding one only the shortfall. Why this split and not the
+  allocator's shares: the hold is maintenance and outranks the others' use
+  (owner order), and the owner rule for an Off battery is the same, "give way
+  only for the shortfall". A battery Off by its mode (P_MODE, below
+  maintenance) therefore still gives before the holding one.
+- Below the aim nothing changes: the floor is 0 W, the hold is 0 W, the rows
+  are identical to before (test_safety86.py part 2).
+- A site stop (a SET above `P_PEAK`) decides alone: nothing is raised at N>=2,
+  and the refiled floor at N=1 stays under `P_SAFETY`. If another battery is
+  pinned to charge (a SAFETY-73 probe) the pin is not raised, so the site is
+  never split both ways.
+- The hold resumes by itself: the rule is evaluated each cycle, so when the
+  guard lets go the command is 0 W again.
+
+**The level dips below the target: the hold finishes anyway.** The HOLD does
+not read the level; it ends on its clock (`maintenance_hold_min`). Topping up
+would mean going back to CHARGE, which waits for sun or a cheap window (up to
+36 h, `CHARGE_TIMEOUT_MIN`) while the pack keeps the site's one maintenance
+slot, so the other battery's cycle waits, and then a new full hold that the
+guard can interrupt again. The guard only gives while the quarter is at risk,
+and the next monthly cycle balances again. If the owner wants a top-up
+instead, it is a change to `maintenance.py`'s HOLD branch, not to this rule.
+
+**Not changed.**
+- The peak guard still grades the emptiest battery (SAFETY-32): at N=2 with
+  B under `peak_soc_floor` the floor is limited and A holds even when it is
+  full (SAFETY-87).
+- "Battery is not keeping up" during maintenance (SAFETY-85), the N=2 charge
+  flapping (SAFETY-88) and the N=1 charge headroom sizing are untouched.

goodwe_controller/DOCS.md

@@ -1669,6 +1669,10 @@ gives more than its drain rate, with one battery too (SAFETY-83).
 In a cheap window the battery being filled charges and the others only add
 charge; none gives while it charges. The charge is cut to what keeps the
 15-minute peak at the limit minus `peak_margin_w` (SAFETY-84).
+While a full battery rests after its charge (the hold), it gives just enough
+to keep the 15-minute peak at that aim if the house needs it; with two
+batteries the other one gives first. The hold still ends on its clock
+(SAFETY-86).
 
 #### Capacity-tariff exposure of the grid-following loop
 

goodwe_controller/app/arbiter.py

@@ -79,7 +79,7 @@ P_PEAK = 50           # capacity-tariff peak shaving - costs real money
 # The order in effect: safety limits and the SAFETY-73 refusal > the peak
 # guard > maintenance > modes > trade > loop. A peak floor above a drain still
 # binds: the `drain` site floor at N>=2 (SAFETY-78), refiled at P_MAINTENANCE
-# at N=1 (SAFETY-83). Not a maintenance HOLD at N=1 (DECISIONS/SAFETY-83).
+# at N=1 (SAFETY-83); over a HOLD, `_peak_over_hold()` (SAFETY-86).
 # A cheap-window charge is suspended while the peak guard holds and, at N>=2,
 # sized to the quarter's headroom (SAFETY-84).
 P_MAINT_SHAPE = 40    # maintenance shaping the loop (charge-only)

goodwe_controller/app/main.py

@@ -74,7 +74,7 @@ from .hass import HomeAssistant
 from .inverter import (LINK_STALE_S, UNIT_A, build_roster,
                        roster_entries, roster_names)
 from .maintenance import (
-    DRAIN, IDLE, POWER_MOVING, MaintConfig, Maintenance, MaintResult,
+    DRAIN, HOLD, IDLE, POWER_MOVING, MaintConfig, Maintenance, MaintResult,
     arbitrate as maint_arbitrate,
 )
 from .mqtt import (MODE_CONFIGS_KEY, MODE_LABELS, USE_OFF, USE_ON,
@@ -2533,6 +2533,50 @@ class Controller:
             if c.source == peakguard.SOURCE and c.lo > rate:
                 claims[i] = dataclasses.replace(c, priority=P_MAINTENANCE)
 
+    def _peak_over_hold(self, claims, maint_results) -> None:
+        """SAFETY-86: a peak floor outranks a maintenance HOLD (0 W).
+
+        At N=1 the floor is refiled at P_MAINTENANCE, as for a drain. At N>=2
+        the holding pack gives only what the others cannot: its pin is raised
+        to the floor minus what they may place. A site stop still decides
+        alone. DECISIONS/SAFETY-86-peak-over-hold.md.
+        """
+        hold = {self.actuator_of("maintenance", inv)
+                for inv, res in zip(self.inverters, maint_results)
+                if res.phase == HOLD and res.owns_setpoint}
+        peak = [i for i, c in enumerate(claims)
+                if c.source == peakguard.SOURCE and c.lo > 0.0]
+        if not hold or not peak:
+            return
+        if len(self.inverters) == 1:
+            for i in peak:
+                claims[i] = dataclasses.replace(claims[i],
+                                                priority=P_MAINTENANCE)
+            return
+        if any(c.kind == SET and c.actuator == ACTUATOR_SITE
+               and c.priority > P_PEAK for c in claims):
+            return
+        live = set(self.live_units())
+        others = 0.0
+        for inv in self.inverters:
+            u = self.actuator_of("maintenance", inv)
+            if u in hold or u not in live:
+                continue
+            b = pre_resolve([c for c in claims if c.actuator == u])
+            if b.contradiction:
+                continue
+            p = allocator.pin_w(b)
+            if p is not None and p < 0.0:
+                return          # a pack pinned to charge: never split both ways
+            others += allocator.hi_w(b) if p is None else p
+        give = max(claims[i].lo for i in peak) - others
+        if give <= 0.0:
+            return
+        for i, c in enumerate(claims):
+            if c.source == "maintenance" and c.kind == SET \
+                    and c.actuator in hold:
+                claims[i] = dataclasses.replace(c, value=give)
+
     def _charge_headroom(self, floor: float, claims) -> float:
         """SAFETY-84: at N>=2 a cheap-window charge pulls no more than the
         quarter's headroom under the peak aim (`charge_headroom_w()`), so it
@@ -3905,7 +3949,8 @@ class Controller:
         # business, not this block's: a maintenance DRAIN or HOLD owns the
         # setpoint at P_MAINTENANCE, and a maintenance CHARGE is only ever a
         # P_MAINT_SHAPE limit (40), bound by this floor. A floor above the drain
-        # rate still wins (SAFETY-78 at N>=2, `_peak_over_drain()` at N=1).
+        # rate still wins (SAFETY-78 at N>=2, `_peak_over_drain()` at N=1), and
+        # so does a floor over a HOLD (`_peak_over_hold()`, SAFETY-86).
         #
         # ⚠️ AND IT IS NOT RUN AT ALL WITHOUT P1. `meter_source: off` is the
         # legacy single-entity path: there is no telegram stream, so
@@ -4307,6 +4352,7 @@ class Controller:
                                       reason="maintenance drain",
                                       actuator=self.actuator_of("drain")))
         self._peak_over_drain(claims, maint_results)
+        self._peak_over_hold(claims, maint_results)
         # --- SAFETY-84: a cheap-window charge is a ceiling over the site ----
         charge = self._charge_ceiling(claims)
         if charge is not None:

goodwe_controller/test_safety83.py

@@ -295,11 +295,10 @@ def store_hold():
 
 
 _h_rows, _h, _hb = run(6000.0, 2500, 50, 2000, dur=600.0, store=store_hold())
-check("a maintenance HOLD at N=1 is not changed (DECISIONS/SAFETY-83, not "
-      "changed): the battery stays at 0 W with the house over the limit",
+check("a maintenance HOLD at N=1 now gives way to the guard too (SAFETY-86, "
+      "test_safety86.py): the battery gives with the house over the limit",
       _h.maints[0].phase == "hold" and _h.peak_guard.engaged
-      and _h.peak_guard.floor_w > 0.0
-      and all(cmd(r) == 0.0 for r in _h_rows))
+      and cmd(_h_rows[-1]) > 0.0 and "limited by peak" in _h_rows[-1][6])
 
 print()
 if fails:

goodwe_controller/test_safety86.py

@@ -0,0 +1,366 @@
+"""Runnable check for SAFETY-86: the peak guard outranks the maintenance HOLD.
+`python3 test_safety86.py`
+
+During the HOLD the battery rests full at 0 W (P_MAINTENANCE, above the peak
+floor), so the house imported everything and quarters went over the peak
+limit. Now the holding battery gives what keeps the quarter at the aim: at N=1
+the peak floor is refiled at P_MAINTENANCE, at N>=2 the hold's pin is raised
+to what the other batteries cannot give. Drives the REAL Controller
+(tools/safety84_identity.py's harness). DECISIONS/SAFETY-86-peak-over-hold.md.
+
+1. N=1, house over the aim: every quarter lands on the aim, the hold goes on,
+   no 'Load too high'; without the fix the quarter goes over and it fires.
+2. Under the aim nothing changes, at N=1 and N=2 (rows identical).
+3. N=2, house over the aim: the other battery gives first, the holding one
+   only the shortfall; with battery modes on and B Off too.
+4. A month peak banked above the limit: the aim is that peak - margin.
+5. A safety stop still parks everything, and the hold gives again after.
+6. The level dips below the target: the hold still ends on its clock.
+7. The rule at its boundaries, on claim lists.
+
+Mutations (MUTATION.md, purged copies) are listed in the pull request.
+"""
+
+import logging
+import os
+import sys
+import types
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+sys.path.insert(0, HERE)
+sys.path.insert(0, os.path.join(HERE, "tools"))
+logging.disable(logging.WARNING)
+
+import opt11_identity as rig                                   # noqa: E402
+import safety84_identity as s84                                # noqa: E402
+from app import control as _ctl                                # noqa: E402
+from app import packmode                                       # noqa: E402
+from app.arbiter import (Claim, P_MAINTENANCE, P_PEAK, P_SAFETY,  # noqa
+                         resolve)
+from app.main import Controller                                # noqa: E402
+from app.maintenance import DRAIN, HOLD, IDLE, MaintResult     # noqa: E402
+from app.store import unit_key                                 # noqa: E402
+
+fails = []
+A, B = "inverter-a", "inverter-b"
+AIM = 3450.0            # peak_cap_w 3500 - peak_margin_w 50
+TOL = 10.0              # W over the aim a banked quarter may show (SAFETY-81)
+
+
+def check(name, cond):
+    print(f"  {'ok  ' if cond else 'FAIL'} {name}")
+    if not cond:
+        fails.append(name)
+
+
+def store_hold(n, b_off=False):
+    """A store with battery A in its HOLD from the first cycle."""
+    s = rig._Store()
+    for k in ("phase", "phase_started"):
+        s.data[k if n == 1 else unit_key(A, k)] = (
+            "hold" if k == "phase" else rig.BASE.isoformat())
+    if b_off:
+        s.data[unit_key(B, packmode.USE_KEY)] = False
+    return s
+
+
+def full(u, t):
+    """A rests full; B is half full."""
+    return 99.0 if u == "a" else 60.0
+
+
+def run(house, n, *, hold_min=600, b_off=False, extra=None, **kw):
+    kw.setdefault("soc", full)
+    kw.setdefault("dur", 2700.0)
+    return s84.run(n, load=house if callable(house) else lambda t: house,
+                   cheap=False, store=store_hold(n, b_off),
+                   extra=dict({"maintenance_hold_min": hold_min},
+                              **(extra or {})), **kw)
+
+
+def without_fix(fn):
+    real = Controller._peak_over_hold
+    Controller._peak_over_hold = lambda self, claims, results: None
+    try:
+        return fn()
+    finally:
+        Controller._peak_over_hold = real
+
+
+def cmd(r):
+    return dict(r[2])
+
+
+def banked(c):
+    return [b.offtake_avg_w for b in c.p1.blocks]
+
+
+def on_aim(c, aim=AIM):
+    b = banked(c)
+    return len(b) >= 2 and all(aim - TOL <= v <= aim + TOL for v in b)
+
+
+def alarmed(c):
+    """Did SAFETY-81's 'Load too high' alarm fire on this run?"""
+    return any("PEAK_GUARD_SATURATED" in e for e in c.events)
+
+
+def refused(rows):
+    return sum(1 for r in rows if r[7] and "REFUSED" in r[7])
+
+
+def peak_prio(r):
+    return [c[1] for c in r[-1][0] if c[0] == "peak"]
+
+
+def hold_pin(r):
+    return [c[3] for c in r[-1][0] if c[0] == "maintenance" and c[2] == "set"]
+
+
+# ============================================================================ #
+print("1. N=1: a house over the aim during the HOLD")
+N1 = {h: run(h, 1) for h in (5000.0, 6500.0, 7000.0)}
+N1_OLD = {h: without_fix(lambda: run(h, 1)) for h in N1}
+for h in N1:
+    print(f"    house {h:.0f}: banked {[round(v) for v in banked(N1[h][1])]} W"
+          f" (before the fix {[round(v) for v in banked(N1_OLD[h][1])]} W), "
+          f"last {N1[h][0][-1][6]}")
+check("⭐ every quarter lands on the aim (3450 W) for a 5000, 6500 and "
+      "7000 W house, and 'Load too high' never fires",
+      all(on_aim(c) and not alarmed(c) for _r, c in N1.values()))
+check("...the battery gives, raised for the peak limit, and stays in its "
+      "HOLD: the phase is hold and the claim still says so",
+      all(c.maints[0].phase == HOLD and cmd(rows[-1])["a"] > 1000.0
+          and "limited by peak" in rows[-1][6]
+          and c.why_words.endswith("raised for the peak limit")
+          for rows, c in N1.values()))
+check("non-vacuous: without the fix the battery sits at 0 W, the quarter "
+      "banks the whole house and 'Load too high' fires",
+      all(all(cmd(r)["a"] == 0.0 for r in rows) and min(banked(c)) >= h - 1
+          and alarmed(c) for h, (rows, c) in N1_OLD.items()))
+
+
+def hob(t):
+    """A 6000 W house with a 5 s spike to 11000 W every 150 s."""
+    return 11000.0 if t % 150 < 5 else 6000.0
+
+
+_sp_rows, _sp = run(hob, 1)
+check("...and 5 s spikes that saturate the guard for a cycle do not fire it "
+      "(SAFETY-81's 10 s hold)",
+      any(r[-1][1] and r[-1][1][1] >= 5000.0 for r in _sp_rows)
+      and not alarmed(_sp))
+
+# ============================================================================ #
+print("\n2. under the aim the HOLD is as before")
+BELOW = {(n, h): (run(h, n, dur=1800.0),
+                  without_fix(lambda: run(h, n, dur=1800.0)))
+         for n, h in ((1, 1200.0), (1, 3000.0), (1, -1500.0),
+                      (2, 1500.0), (2, 3000.0), (2, 5000.0))}
+check("⭐ N=1 at a 1200 W and 3000 W house and a 1500 W surplus, N=2 at "
+      "1500, 3000 and 5000 W (B covers it): battery A is at 0 W on every "
+      "cycle and every row equals the run without the fix",
+      all(all(cmd(r)["a"] == 0.0 for r in new[0]) and new[0] == old[0]
+          for new, old in BELOW.values()))
+check("...and the peak claim stays at P_PEAK on every cycle",
+      all(p == P_PEAK for new, _o in BELOW.values() for r in new[0]
+          for p in peak_prio(r)))
+
+# ============================================================================ #
+print("\n3. N=2: the other battery gives first, the holding one the rest")
+N2 = {h: run(h, 2) for h in (6500.0, 7000.0)}
+N2_OLD = {h: without_fix(lambda: run(h, 2)) for h in N2}
+for h, (rows, c) in N2.items():
+    print(f"    house {h:.0f}: banked {[round(v) for v in banked(c)]} W "
+          f"(before the fix {[round(v) for v in banked(N2_OLD[h][1])]} W), "
+          f"last {rows[-1][2]}")
+check("⭐ house 6500 and 7000 W, B at most 2500 W: every quarter lands on "
+      "the aim, nothing is refused or split both ways, no 'Load too high'",
+      all(on_aim(c) and refused(rows) == 0 and not alarmed(c)
+          and all(cmd(r)["a"] * cmd(r)["b"] >= 0.0 for r in rows)
+          for rows, c in N2.values()))
+_gives = [r for rows, _c in N2.values() for r in rows if cmd(r)["a"] > 0.0]
+check("⭐ A gives only the shortfall: on every cycle A gives, B is at its "
+      "2500 W and A's pin is the guard's floor minus 2500 W",
+      len(_gives) > 500
+      and all(cmd(r)["b"] == 2500.0 and hold_pin(r)
+              and abs(hold_pin(r)[0] - (r[-1][1][1] - 2500.0)) < 1e-6
+              for r in _gives))
+check("...A stays in its HOLD, and its last command is the shortfall "
+      "(6500 - 3450 - 2500 = 550 W, give or take the meter's 1 W)",
+      all(c.maints[0].phase == HOLD for _r, c in N2.values())
+      and 540.0 <= cmd(N2[6500.0][0][-1])["a"] <= 560.0)
+check("non-vacuous: without the fix A sits at 0 W, the quarter goes over "
+      "the limit and 'Load too high' fires",
+      all(all(cmd(r)["a"] == 0.0 for r in rows) and max(banked(c)) > 3900.0
+          and alarmed(c) for rows, c in N2_OLD.values()))
+
+_off_rows, _off = run(6500.0, 2, b_off=True,
+                      extra={"battery_modes_enabled": True})
+print(f"    B Off, house 6500: banked {[round(v) for v in banked(_off)]} W, "
+      f"last {_off_rows[-1][2]}")
+check("⭐ battery modes on, B Off: the Off battery still gives before the "
+      "holding one (maintenance outranks a mode), the quarter lands on the "
+      "aim, nothing refused",
+      on_aim(_off) and cmd(_off_rows[-1])["b"] == 2500.0
+      and 540.0 <= cmd(_off_rows[-1])["a"] <= 560.0
+      and refused(_off_rows) == 0 and not alarmed(_off))
+
+# ============================================================================ #
+print("\n4. a month peak banked above the limit")
+BANK = {n: (run(6500.0, n, month_peak=4000.0),
+            without_fix(lambda: run(6500.0, n, month_peak=4000.0)))
+        for n in (1, 2)}
+for n, (new, old) in BANK.items():
+    print(f"    N={n} house 6500, month peak 4000: banked "
+          f"{[round(v) for v in banked(new[1])]} W (before the fix "
+          f"{[round(v) for v in banked(old[1])]} W)")
+check("⭐ under a month peak of 4000 W the aim is 3950 W (peak - margin), "
+      "at N=1 and N=2, and no 'Load too high'",
+      all(on_aim(new[1], 3950.0) and not alarmed(new[1])
+          for new, _old in BANK.values()))
+check("non-vacuous: before the fix N=1 banks the whole house and N=2 banks "
+      "4000 W, over that aim",
+      min(banked(BANK[1][1][1])) >= 6499.0
+      and min(banked(BANK[2][1][1])) >= 3999.0)
+
+# ============================================================================ #
+print("\n5. a safety stop still wins")
+
+
+def blind_at(t0, t1):
+    """A's power reading is missing from `t0` to `t1`: a site safety SET."""
+    def before(c, t):
+        s84.feed(False)(c, t)
+        if not getattr(c.hass, "_blind", False):
+            real = c.hass.number
+
+            async def number(e, invert=False):
+                if e == "sensor.batt_a" and t0 <= c.hass.t < t1:
+                    return None
+                return await real(e, invert)
+            c.hass.number, c.hass._blind = number, True
+    return before
+
+
+STOP = {n: run(6500.0, n, dur=900.0, before=blind_at(300.0, 600.0))
+        for n in (1, 2)}
+for n, (rows, _c) in STOP.items():
+    print(f"    N={n} reading lost 300-600 s: at {rows[100][0]:.0f} s "
+          f"{rows[100][2]}, {rows[100][6]}; after {rows[-1][2]}")
+check("⭐ with a reading gone the safety SET parks every battery at 0 W, at "
+      "N=1 and N=2, with nothing refused",
+      all(all(v == 0.0 for r in rows if 330.0 <= r[0] < 600.0
+              for v in cmd(r).values())
+          and any(r[6].startswith("safety -> 0 W") for r in rows)
+          and refused(rows) == 0 for rows, _c in STOP.values()))
+check("...the hold gave before the stop and gives again after it",
+      all(cmd(rows[50])["a"] > 0.0 and cmd(rows[-1])["a"] > 0.0
+          for rows, _c in STOP.values()))
+
+# ============================================================================ #
+print("\n6. the level dips below the hold's target")
+
+
+def draining(u, t):
+    """A's level falls 1 % a minute from 99 % (set, not integrated); B 60 %."""
+    return max(20.0, 99.0 - t / 60.0) if u == "a" else 60.0
+
+
+DIP = {n: run(6500.0, n, hold_min=30, dur=2400.0, soc=draining)
+       for n in (1, 2)}
+for n, (rows, c) in DIP.items():
+    print(f"    N={n}: phases {sorted({tuple(x[-1][3]) for x in rows})}, "
+          f"last event {[e for e in c.events if 'maintenance' in e][:1]}")
+check("⭐ the level falls from 99 % to 70 % while the hold gives, and "
+      "the hold still ends on its 30 min clock: HOLD -> IDLE, cycle "
+      "COMPLETE, never back to CHARGE, at N=1 and N=2",
+      all(c.maints[0].phase == IDLE
+          and any("cycle COMPLETE" in e for e in c.events)
+          and {x[-1][3][0] for x in rows} == {HOLD, IDLE}
+          and all(x[-1][3][0] == HOLD for x in rows if x[0] < 1795.0)
+          for rows, c in DIP.values()))
+check("...the hold gave on the way (the level really dipped)",
+      all(any(cmd(r)["a"] > 0.0 for r in rows if r[0] < 1795.0)
+          for rows, _c in DIP.values()))
+
+# ============================================================================ #
+print("\n7. the rule at its boundaries")
+_c = run(1500.0, 2, dur=10.0)[1]
+_c1 = run(1500.0, 1, dur=10.0)[1]
+HOLDING = [MaintResult(HOLD, True, 0.0, False, []),
+           MaintResult(IDLE, False, None, False, [])]
+
+
+def pin_after(floor, *extra, live=(A, B), results=HOLDING, c=_c):
+    fake = types.SimpleNamespace(inverters=c.inverters,
+                                 actuator_of=c.actuator_of,
+                                 live_units=lambda: tuple(live))
+    cl = [Claim.limit("supervised", P_SAFETY, -2500.0, 2500.0, actuator=A),
+          Claim.limit("supervised", P_SAFETY, -2500.0, 2500.0, actuator=B),
+          Claim.set("maintenance", P_MAINTENANCE, 0.0, HOLD, actuator=A),
+          Claim.limit("peak", P_PEAK, lo=floor, reason="quarter peak"),
+          *extra]
+    Controller._peak_over_hold(fake, cl, results)
+    return next((x.value for x in cl
+                 if x.source == "maintenance" and x.kind == "set"), None), cl
+
+
+check("⭐ at N=2 a floor under or at B's 2500 W leaves A at 0 W (never "
+      "charging); 0.5 W above it raises A's pin to 0.5 W",
+      pin_after(1000.0)[0] == 0.0 and pin_after(2500.0)[0] == 0.0
+      and pin_after(2500.5)[0] == 0.5)
+check("⭐ B not live, contradicting itself, or refusing to give: A gives the "
+      "whole floor",
+      pin_after(2000.0, live=(A,))[0] == 2000.0
+      and pin_after(2000.0, Claim.limit("pack", P_SAFETY, 10.0, -10.0,
+                                        actuator=B))[0] == 2000.0
+      and pin_after(2000.0, Claim.limit("refused", P_SAFETY, hi=0.0,
+                                        actuator=B))[0] == 2000.0)
+_probe = _ctl.PROBE_W
+check("⭐ B probing: giving counts its probe (A gives the rest), charging "
+      "leaves A at 0 W so the site is never split both ways",
+      pin_after(2000.0, Claim.set("refused", P_SAFETY, _probe, "probe",
+                                  actuator=B))[0] == 2000.0 - _probe
+      and pin_after(2000.0, Claim.set("refused", P_SAFETY, -_probe, "probe",
+                                      actuator=B))[0] == 0.0)
+_p, _cl = pin_after(4000.0, Claim.set("safety", P_SAFETY, 0.0,
+                                      "inputs missing"))
+check("⭐ a site safety SET: A stays at 0 W and the site resolves to 0 W; "
+      "a unit safety SET on B does not stop A giving",
+      _p == 0.0 and resolve(_cl, units=(A, B), live={A, B}).target_w == 0.0
+      and pin_after(3000.0, Claim.set("failsafe", P_SAFETY, 0.0,
+                                      actuator=B))[0] == 3000.0)
+check("only a HOLD: a DRAIN pin or an idle pack is not raised",
+      pin_after(4000.0, results=[MaintResult(DRAIN, True, 0.0, False, []),
+                                 HOLDING[1]])[0] == 0.0
+      and pin_after(4000.0, results=[HOLDING[1], HOLDING[1]])[0] == 0.0)
+
+
+def refile(lo, results=(HOLDING[0],)):
+    fake = types.SimpleNamespace(inverters=_c1.inverters,
+                                 actuator_of=_c1.actuator_of)
+    cl = [Claim.set("maintenance", P_MAINTENANCE, 0.0, HOLD),
+          Claim.limit("peak", P_PEAK, lo=lo, reason="quarter peak")]
+    Controller._peak_over_hold(fake, cl, list(results))
+    return cl
+
+
+check("⭐ at N=1 a floor of 0 W stays at P_PEAK, 0.5 W is refiled at "
+      "P_MAINTENANCE, and a blind claim (a ceiling only) is not refiled",
+      refile(0.0)[1].priority == P_PEAK
+      and refile(0.5)[1].priority == P_MAINTENANCE
+      and refile(float("-inf"))[1].priority == P_PEAK)
+_stop = refile(3000.0) + [Claim.set("safety", P_SAFETY, 0.0,
+                                    "inputs missing")]
+check("⭐ at N=1 a refiled floor stays under a safety SET: 0 W",
+      resolve(_stop).target_w == 0.0)
+check("at N=1 outside a HOLD the claim is not touched by this rule",
+      refile(3000.0, (MaintResult(IDLE, False, None, False, []),))[1]
+      .priority == P_PEAK)
+
+print()
+if fails:
+    print(f"{len(fails)} FAILED: " + ", ".join(fails))
+    sys.exit(1)
+print("all SAFETY-86 checks passed")