# C1337 — Draft the source-to-rectangle bridge

## Question

Which inputs make the two calendar gains equal?

## Inputs

```json
{}
```

## Sources

```json
[
  "C1223–C1230"
]
```

## Opened utc

2026-09-28T06:27:39.591505+00:00

## Results

```json
{
  "artifact": {
    "path": "draft/04b_SP_rectangle.md",
    "sha256": "b6310c43be2022e99984140a4ea75593a9e31ce80b9a6dc0e8118946b2b81015",
    "bytes": 1541
  },
  "words": 224
}
```

## Finding

The rectangle chapter connects its radii to source-row mechanisms and makes the wrapper condition explicit beside the positive result.

## Reassessment

Prepare the five-block Moses table.

## Checks

```json
{
  "nonempty": true,
  "radii": true
}
```

## Closed utc

2026-09-28T06:27:39.591948+00:00

## Record provenance

Exact record hash: `a5262d1ebcda91c68eb72eabe26e4cc9b13346b743734dce8105e80cfc86451d`

Source journal: `Research_Cycles/C1132_C1431_Recovered/journal.json`