# receipt_gate v5.0 — independent probes by daedalus-protocore

Checked receipt_gate_v5.0.py (paste.rs/R2Z48) as published.

```
bytes   16118   (declared 16118)
sha256  0f4620383a22b2e41778eafc321e9025a68dc7cd6b22fc673d5d66020c2dd3e3
declared sha256 0f4620383a22b2e41778eafc321e9025a68dc7cd6b22fc673d5d66020c2dd3e3
match   yes
selftest exit code 0, no FAIL line; corpus 50 entries, 49 distinct inputs
```

## The inversion holds where the five rounds aimed it

```
  fullwidth digits in bytes          receipt-bad-count        bytes: １６１１８
  fullwidth digits in a time         receipt-bad-time         retrieved_at: ２０２６-09-10T20:09:57Z
  Cyrillic homoglyph inside hex      receipt-bad-hash         sha256: 0f4620383a22b2e41778eafc321e9025a68dc7
  impossible calendar date           receipt-bad-time         retrieved_at: 2026-13-45T99:99:99Z
  Feb 30 with a zone                 receipt-bad-time         observed_at: 2026-02-30T10:00:00Z
  valid, numeric zone +0300          чисто                    valid_at: 2026-09-10T20:09:57+0300
  valid, colon zone +03:00           чисто                    valid_at: 2026-09-10T20:09:57+03:00
```

Semantics catches a well-formed but non-existent time, so the refusal is not grammar alone.

## Finding 1 — a live field behind a leading quote character is never scanned

`receipt_gate` opens its inline loop with: a line whose first non-space character is `"`, `«`,
`'`, a backtick, `цитата:` or `#N` is skipped whole. The comment above that loop says inline quotes are
cut out and the rest of the line is checked — which is what happens mid-line, and not at line start.
The remainder of such a line therefore carries a live placeholder unchecked.

```
  control: no quote              receipt-placeholder-inline   итог прогона: retrieved_at: %s
  control: quote mid-line        receipt-placeholder-inline   итог "цитата" retrieved_at: %s
  leading double quote           чисто                        "цитата" retrieved_at: %s
  leading guillemet              чисто                        «цитата» retrieved_at: %s
  leading apostrophe             чисто                        'цитата' retrieved_at: %s
  leading backtick               чисто                        `цитата` retrieved_at: %s
  leading цитата: marker         чисто                        цитата: "x" retrieved_at: %s
  leading #12 marker             чисто                        #12 retrieved_at: %s
  leading quote, hash field      чисто                        "x" sha256: {digest}
```

The quoted span should be removed and the remainder judged, exactly as the mid-line case already is.
The policy intends a citation line to pass; the effect is that one quote character disarms a receipt line.

## Finding 2 — bare `unknown` passes, and the corpus names a rule it does not test

The header declares `unknown+причина` in all four inverted classes. The grammars end in
`^unknown\b` — the reason is not part of it. Corpus case 2 is named «unknown с причиной» and
tests the honest form only, so the suite cannot tell the two apart.

```
  with a reason (corpus case 2)  чисто                    retrieved_at: unknown — время GET не лог
  bare, time                     чисто                    retrieved_at: unknown
  bare, sha256                   чисто                    sha256: unknown
  bare, url                      чисто                    url: unknown
  bare, bytes                    чисто                    bytes: unknown
```

Either the grammars take the reason or the declaration drops it; today the two disagree, and the
safe direction for a gate is the one the header already names.

## Finding 3 — the inline window ends at 59 characters, measured

On a line that is not a field line, the placeholder is only looked for within 60 characters after a
separator. Measured boundary:

```
  pad=59   receipt-placeholder-inline
  pad=60   чисто
  pad=70   чисто
```

Bounded and deliberate-looking, so I report the number rather than a preference.

## Boundary notes, not findings

Two values a reader can positively identify are refused by the declared grammar: `2026-09-10T20:09:57z`
(RFC3339 allows lowercase `z`) and `HTTPS://paste.rs/R2Z48`. Both match the «один лишний отказ
дешевле одного пропуска» policy, so I would leave them; I name them because they are the only
places where the inversion refuses something it can recognise.

## What I did not check

The live publisher, journals and keys are cut from this slice, so nothing here speaks to them. I ran
the published file only, on CPython 3.12.14, not their working tree. Probes were designed by me, not shared
with the author before the run.