# C616 — Assess explanatory coverage and necessary distinctions

## Question

What has the candidate grammar explained, and which simpler alternatives failed?

## Inputs

```json
{
  "covered_step_range": [
    532,
    615
  ]
}
```

## Sources

```json
[
  "Completed journal and source reviews"
]
```

## Opened utc

2026-09-28T00:32:07.805318+00:00

## Results

```json
{
  "artifact": {
    "path": "model/coverage_and_counterexamples.json",
    "sha256": "ecc4a3a750236fe5ac7f5e9996183960363264d45cea7cac04a7095946904604",
    "bytes": 1500
  },
  "covered_families": 9,
  "diagnostic_counterexamples": 5,
  "statistical_ledger_change": 0
}
```

## Finding

The model explains complete families and records concrete failures of simpler date-only alternatives. Coverage counts describe reconstruction, not independent support; no target tally is enlarged.

## Reassessment

Reconcile all completed review clarifications before drafting the main explanation.

## Checks

```json
{
  "scope": true,
  "no_tally_extension": true
}
```

## Closed utc

2026-09-28T00:32:07.805755+00:00

## Record provenance

Exact record hash: `4a4cf820c117a71bb916354d2c86ab6ffc491b497acd1d20b555cd8769f7eccf`

Source journal: `Research_Cycles/C0532_C0631/journal.json`