> For the complete documentation index, see [llms.txt](https://docs.qwertycoin.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.qwertycoin.org/epose/epochs-and-qualification.md).

# Epochs and Qualification

> **Verified against:** the latest stable release; exact review revisions are recorded in [Pinned source and release revisions](/contribution-and-evidence/source-version-matrix.md).

> **Compiled mainnet profile:** 720-block epochs, 60-block anchor depth, rounds at offsets 0/200/400, at least 2 successful rounds.

For normal epochs `E > 0`:

```
start(E)             = 720 * E
end(E)               = start(E) + 719
enrollment_cutoff(E) = start(E) - 61
committee_anchor(E)  = start(E) - 60
evidence_deadline(E) = end(E) - 60
```

| Epoch | Start |   End |       Enrollment cutoff |        Committee anchor | Evidence deadline |
| ----: | ----: | ----: | ----------------------: | ----------------------: | ----------------: |
|     0 |     0 |   719 | activation special case | activation special case |               659 |
|     1 |   720 |  1439 |                     659 |                     660 |              1379 |
|     2 |  1440 |  2159 |                    1379 |                    1380 |              2099 |
|    15 | 10800 | 11519 |                   10739 |                   10740 |             11459 |

Do not apply negative pre-epoch formulas to epoch 0. Epoch 0 is activation; epoch 1 is the first service epoch. Membership freezes **before** records in the anchor block are applied, so cutoff-height records can qualify for membership but anchor-height records cannot. Qualification closes **after** records in the inclusive evidence-deadline block are applied.

For each subject and round:

```
actual_committee = min(9, frozen_population - 1)
required_receipts = ceil(2 * actual_committee / 3)
```

Thus 6 receipts is required only for a full 9-verifier committee. With 4 frozen identities, a subject has 3 possible verifiers and needs `ceil(2*3/3)=2` distinct receipts per passing round. Empty/one-member snapshots cannot form an independent committee and qualify nobody.

Distinct authorized verifier keys count per round; duplicates or receipts from another round cannot fill a missing round. For a full committee:

| Canonical R0 / R1 / R2 | Result after closure                   |
| ---------------------- | -------------------------------------- |
| 6 / 6 / 0              | Qualified                              |
| 9 / 1 / 0              | Not qualified; only one round passes   |
| 0 / 6 / 6              | Qualified                              |
| 5 / 5 / 5              | Not qualified; no round reaches quorum |

Before the set closes, state is `pending`. After closure it is `qualified` or `not_qualified`. Missing chain/snapshot evidence is `unknown`/unavailable, never zero.