# C847 — Resolve the female register as a two-endpoint measurement

## Question

How do400/430/470/490 arise when the chronological endpoints also change?

## Inputs

```json
{}
```

## Sources

```json
[
  "File58 §13.2"
]
```

## Opened utc

2026-09-28T02:34:10.947709+00:00

## Results

```json
{
  "female_source_counts": [
    200,
    200,
    30,
    40,
    20
  ],
  "prefix_register": [
    200,
    400,
    430,
    470,
    490
  ],
  "chronology_heads": [
    1846,
    1876,
    1876,
    1896
  ],
  "chronology_tails": [
    1446,
    1446,
    1406,
    1406
  ],
  "span_changes": [
    {
      "head": 30,
      "tail": 0,
      "span": 30
    },
    {
      "head": 0,
      "tail": -40,
      "span": 40
    },
    {
      "head": 20,
      "tail": 0,
      "span": 20
    }
  ]
}
```

## Finding

The30,40,20 increments come respectively from an earlier head, a later tail, and an earlier head. This is a two-endpoint span register, not one chronology walk from a fixed anchor.

## Reassessment

Test a second list’s declared regroupings against the same measurement grammar.

## Checks

```json
{
  "register": true,
  "spans": true,
  "response": true
}
```

## Closed utc

2026-09-28T02:34:10.948250+00:00

## Record provenance

Exact record hash: `75a3eecb4487f377d76dae23d3fa35c90c40d9b1c4d5bbde0a992478b86c4f62`

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