# C879 — Prove the whole-field integer obstruction

## Question

Can changing a common anchor put every image head on integer years?

## Inputs

```json
{}
```

## Sources

```json
[
  "File46 §6A.5",
  "C878"
]
```

## Opened utc

2026-09-28T02:48:04.557389+00:00

## Results

```json
{
  "gaps": [
    430,
    30,
    430
  ],
  "image_gaps": [
    "10750/23",
    "750/23",
    "10750/23"
  ],
  "proof": {
    "path": "model/File46_integer_obstruction.json",
    "sha256": "5b51b11b5cdba7e6ceec0e04132f39ab96d0d32cbb46300872e0800f792cc495",
    "bytes": 441
  }
}
```

## Finding

No common anchor can make every File46 head integral: the transformed430 and30 gaps are nonintegral independently of anchor. Whole-field shape is preserved, while whole-grid membership fails.

## Reassessment

Derive the stagewise grid criterion for a fixed Key word.

## Checks

```json
{
  "all_obstructions": true,
  "anchor_free": true,
  "specific": true
}
```

## Closed utc

2026-09-28T02:48:04.558892+00:00

## Record provenance

Exact record hash: `93a628c354602dee2c66addcd396b1af8846d82ec803458ef2fb951bbc2316e7`

Source journal: `Research_Cycles/C0832_C0931/journal.json`