EpochTransition

The coin of the base-address outputs of utxos, per stake credential, the ledger's InstantStake: pointer, enterprise and Byron addresses add nothing (StakeRefBase only, conway State/Stake.hs:101-121), spec [SN-2], [SN-5]. EmulatorBase.stakeDistribution reads it too, spec [DM-15] (D80).

The reward update of an epoch, startStep and completeRupd run in one go (shelley LedgerState/PulsingReward.hs:99-212, 242-280; Rewards.hs:86-157, 291-393), ledger-rules spec [RW-1], [RW-2], [RW-13] to [RW-20], with exact rationals floored where the ledger floors, [RW-19].

At PV >= 7 only, [RW-20]: rewards summed per credential and no registration prefilter; [EB-5] checks registration when it pays. Under Ideal, eta = 1 and every pool of go with stake earns with appPerf = 1, [RW-15], D70. The ledger's crashes become rules: expectedBlocks = 0 [RW-14], totalStake <= 0 [RW-16], nOpt = 0 [RW-17] (D71, D83).

The stake snapshot of ledger, snapShotFromInstantStake (cardano-ledger-core State/SnapShots.hs:418-430), spec [SN-1] to [SN-8], [SN-10].

• activeStake: each registered account that delegates to a pool, with the coin of the base-address outputs of its credential plus its balance, when that is above 0 (resolveActiveInstantStakeCredentials, State/Stake.hs:220-246), [SN-2] to [SN-5]. As in the ledger, the pool is not checked: DELEG accepts a delegation only to a registered pool, and POOLREAP clears the delegations to a retired one.
• pools: every pool in stakePools, with its current params (resetStakePoolsSnapShot, State/SnapShots.hs:409-416), [SN-7]; the delegators of each are found by a scan of the accounts, [SN-10], since Scalus keeps no delegator set (D22, D51), and its fields are those of mkStakePoolSnapShot (:187-216), [SN-8].

Spec [EB-18]: the deposits the ledger owes, totalObligation (shelley LedgerState/Types.hs:690-691): the deposits of the accounts, pools and DReps of certState (conwayObligationCertState, conway State/CertState.hs:112-117) and of the proposals of govState (obligationGovState, conway Governance.hs:416-422). The Emulator genesis starts with it too, D52.

The ledger state, the epoch state and the current pparams after the epoch transition into epoch boundary, spec [EB-4], [EB-25], D88. env.params are the current pparams before it.

The steps run in the order of the table of spec section 12.2. A step whose phase has not landed is identity, spec [EB-24]. First [EB-5] applies pendingRewards (conway Rules/NewEpoch.hs:172-178), so SNAP sees the paid rewards and the reduced fees. Then, as conway Rules/Epoch.hs:276-378 runs them: SNAP ([EB-6]), POOLREAP ([EB-7] to [EB-9]), the pparams of the enact state ([EB-13]), the enactment of the pending ratify result ([EB-10] to [EB-14]), the voting state ([EB-15], [EB-16]), the treasury ([EB-17]), HARDFORK ([EB-19]) and RATIFY ([EB-20]), then deposited ([EB-18]) on the result: neither HARDFORK nor RATIFY changes a deposit. The blocks made move to the previous epoch and the last epoch becomes boundary, [EB-21] (conway Rules/NewEpoch.hs:182-192). Last, [EB-22] replaces pendingRewards with the reward update of the new epoch, [RW-21], read from the reserves after [EB-5] and from prevParams after [EB-13], [EB-22a].