# L5 — `ComputeBudget` compare at the interest boundary, with a failing control

VM146, 2026-09-08. Input save `turn1-state.sav` (= `Autosave EndTurn - turn2.sav`, 64,967 B,
sha256 `a3f9dc4b49fc669c…`). Identical UI path for all three runs.

## Runs

| run | build | `hooks` | `ComputeBudget` | dll md5 |
|---|---|---|---|---|
| control | `l5A-widened` | `off` | not installed | `F8DFC4AEE31FA60C5A2BE1E70CC38633` |
| A | `l5A-widened` | `trace` | `compare` | `F8DFC4AEE31FA60C5A2BE1E70CC38633` |
| B | `l5B-decimal-CONTROL` | `trace` | `compare` | `0FCC19DC2B9A769DB5FE2C4DC4683C78` |

A and B are the same source except `kSavingsInterestRate` / `kDebtInterestRate`: widened floats
in A, exact decimals in B. That is our side of the compare only.

## tracecmp

```
A   calls 3895   compared 3895   diverged    0   invalid 0   undeclared writes 0
B   calls 2718   compared 2718   diverged 1359   invalid 0   undeclared writes 0
```

## Coverage — distinct states, not call counts

| treasury (`Sav`) | multiple of 100 | calls (A) | calls (B) | diverged (B) | game `savingsInterest` | exact decimal |
|---:|---|---:|---:|---:|---:|---:|
| 0 | — | 303 | 303 | 0 | 0 | 0 |
| 38,100 | **yes** | 1 | 1 | **1** | 380 | 381 |
| 50,000 | **yes** | 1,371 | 1,358 | **1,358** | **499** | 500 |
| 92,651 | no | 28 | 28 | 0 | 926 | 926 |
| 289,688 | no | 2,192 | 1,028 | 0 | 2,896 | 2,896 |

**5 distinct treasury states, 2 on the rounding boundary.** Compare with the run this replaces:
4,437 calls, 20 distinct states, none on a boundary.

`projected` split in A: 3,888 turn-path, 7 UI.

Diverging fields in B (per call): `savingsInterest` 1,359, `available` 1,359, `researchMoney`
1,317. Sample diff at `Sav = 50,000`:

```
side.budget.after.v.savingsInterest   orig 499     ours 500
side.budget.after.v.available         orig 239091  ours 239092
side.budget.after.v.researchMoney     orig 59772   ours 59773
```

## Live constants, read on every one of A's 3,895 records

```
savingsInterestRate   0.009999999776482582   = (double)0.01f
debtInterestRate      0.15000000596046448    = (double)0.15f
researchYieldFactor   0.8500000238418579     = (double)0.85f
protectionFactor      3.29999995             = (float)3.3   [slot non-null; file image is zero]
```

## Live per-player flags (all 8 players of `turn1-state`)

| PlyrIdx | isAI | npc | ownedSystems | aidf |
|---:|---|---|---:|---:|
| 0 | false | false | 1 | 1 |
| 1 | **true** | false | 1 | 1 |
| 2 | true | true | 0 | 1 |
| 3 | true | true | 0 | 1 |
| 4 | true | true | 0 | 1 |
| 5 | true | true | 0 | 1 |
| 6 | true | true | 0 | 1 |
| 7 | true | true | **1** | 1 |

Exactly one AI-and-not-NPC player; the human is neither; player 7 owns a system and is an NPC,
which is why T31 calls it ambiguous.

`researchMoney`: 9 distinct values across A (`0, 24717, 59772, 59922, 60521, 68047, 217752,
218204, 218508`). **None is a multiple of 40,000**, so the research-yield-factor width is
unexercised.

## Autosaves

| run | `(Autosave EndTurn).sav` | `(Autosave).sav` |
|---|---|---|
| control | `a3f9dc4b49fc669c…` | `62061918176e3441…` |
| A | `a3f9dc4b49fc669c…` | `7fc9e6ab46b47794…` |
| B | `a3f9dc4b49fc669c…` | `ab4ac2d7e2977260…` |

Pre-turn identical in all three. Post-turn differs by exactly four leaves per pair, all in one
shadow empire's AI research pick — **not the hook**; see
`findings/subsystems/turn1-to-turn2-nondeterminism.md`.