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5 Commits
Author SHA1 Message Date
swaitsandClaude Opus 5.5 d7fa16e974 feat(arap)!: documents read their figures from standing lines; control accounts
check / check (push) Canceled after 0s
refuse hand entries (P4b S1, part A)

Plan P4b (D-45), slice S1, the engine half: rules.md B-38.

- ledger-core: every receivables or payables line carries its document
  (Ledger.line_docs: DocRef, Movement, DocTag), written by the document
  commands in the step that posts it, derived on replay from the existing
  document events (the role's account as it stood then; payments by the
  ordinal rule), copied onto a reversal's mirror. Ledger::stands_on;
  doc_state / invoice_state / bill_state (total, paid, outstanding,
  status Open/Partial/Paid/WrittenOff/Void, overdue days) as of any day;
  ar_aging / ap_aging read them, so reversed payments and voids are right.
  The control guard (add_line, add_line_fx, post_entry,
  register_recurring) refuses untagged lines on receivables/payables,
  exempting a reversal's mirror of a legacy line; replay never refuses.
  Bounds (kernel::running_bounds, bounds_kept) on payments and reversals;
  a document reversal never dated before its entry; deposit/payer accounts
  must be cash-like and hold no role. New API: receive_payment_with /
  pay_bill_with (PaymentDetails: instrument, reference), void_document /
  check_void_document, control_check, payments_recorded,
  standing_payments, replay_reverse_entry. Invoice.amount_paid/status
  remain only as derived caches for the MCP layer until part B.
  cashflow bill_splits reads payments from the tags.
- ledger-store: journal feature document_standing (D-39 gated) for a
  payment accepted only because an earlier one was reversed;
  receive_payment_with / pay_bill_with (instrument journaled as
  entry.instrument_set, reference in the description), void_document;
  replay uses replay_reverse_entry; schema 15 drops the projection's
  amount_paid/status. Fixture p4-arap-before + golden figures written by
  the version before S1, adjudicated in arap_standing.rs.
- ledger-gui: party card, cash "coming up" and company owed totals read
  doc_state as of today (late from the derived state).
- Lean Documents.lean (control_agrees and friends); Kani
  bounds_check_matches_definition,
bounds_kept_is_the_definition_on_books_in_bounds;
  rules B-38, B-18/B-23 amended; bookspec `older = true` for legacy hand
  lines; tests that hand-post to 1200/2000 post as replay or renumbered.

Review fixes (both reviews of part A):
- control_role_of guards only an account the role is assigned to or one
  holding its documents' lines (a chart's own 1200 Equipment or card at
  2000 is free until a document posts there); payment accounts check
  other roles by holds_role (type-checked). The MCP tests that failed on
  the guard (oracle_mcp, spec_projects) pass unchanged.
- standing_payments leaves out reversals (sorted, deduped); replayed
  tags match the movement's side; payments_recorded counts every payment
  event (tagged or not, Ledger.payment_events) and refuses overflow.
- The record caches settled (paid + discounted + written off) and owed
  (Invoice/Bill.owed, never serialized): a void never reads as paid.
- assign_role: receivables/payables refuse moving onto an account with
  untagged lines (RoleAccountHasHandLines) and, on their control account
  holding a balance, say DocumentRoleHoldsBalance (no hand entry named);
  B-23 reworded. The reversal-mirror exemption only takes a hand line
  off (even chain depth); putting it back is refused.
- DocStatus Overpaid and Unattached; aging leaves out credit balances;
  ControlCheck.attention lists out-of-bounds and unattached documents.
- stands_on counts a chain in order; indexes (doc_index, doc_accounts,
  order_pos, reversed_by) keep the derived figures linear.
- Viewer reads a post-dated document as of its own date; one state per
  row. bounds_kept's side-crossing documented as intended.
- Tests: ten new spec_documents scenarios, stronger proptests, store
  proptest arap_props (live = replay = snapshot at every date, closed
  months), fuzz ops void/payments with details, a GUI post-dated test;
  Lean Step.assign / Step.release with unattached_zero kept; model
  limits stated in docs/testing.md and B-38.
Review fixes (CPA and engineering lenses): only an assigned role's
account or one holding document lines is a control account (a chart's
own 1200 asset stays free); a role can't move onto untagged lines or off
document lines (Lean Step.assign); a void's cache never reads as paid;
no Decimal sum panics; per-document indexes keep figures linear; a
replayed tag matches its side; the feature gate counts payment events;
a payment's reversal is never listed as standing; an overpaid document
has its own status; the viewer keeps post-dated documents.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj
2026-10-24 09:17:42 -06:00
swaitsandClaude Opus 5.5 b0a9fd8ad4 P3: depreciation straight-line by days through the final month, schedules by day (defects 22, 9, D-37)
The final month takes what the months before leave, spread over its days;
a disposed asset stops on its disposal day. A skipped month is caught up
in the month the run is made; a reversed run un-posts its month. New
schedules spread by day; equal-months schedules must start on the 1st.
Amounts round to the currency's own minor unit. Kani and Lean proofs; an
exhaustive search over runs, reversals and disposals.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj
2026-10-21 14:04:11 -06:00
swaitsandClaude Opus 5.5 c2ceabbae9 P3: party totals by what moved the money, once (defects 14, 11, 24)
Each party's part of an entry is signed as its own account would show it,
with a direction and its cash and in-kind amounts; a reversal is its
original negated. Totals on a cash or all basis: for a member, all equals
the members' equity statement and cash the K-1's cash. Money is cash,
cards and the financing accounts, and a liability credit never pays its
own creditor (creditor_of), so accruals and declared distributions count
once. tin_last4 from the TIN or W-9 facts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj
2026-10-21 12:12:26 -06:00
swaitsandClaude Opus 5.5 714caf9be9 lean: apportion's parts sum to the whole for any number of parts
The ranks of n parts are a permutation of 0..n-1 (being ahead is a strict
total order; pigeonhole by hand, core Lean has no subperm), so exactly
u parts get a unit and one gets the fraction. apportion_sum and
apportion_sum_of_shortfall; the audit shows only the standard axioms.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
2026-10-14 10:17:37 -06:00
swaitsandClaude Opus 5.5 2d36fb05a4 feat(core): prove the accounting laws (Kani + Lean); fix three engine gaps
The money arithmetic every invariant rests on now lives in one kernel,
ledger-core/src/kernel.rs: signing a line, totals, net, per-account
movements, reversal, normal balances, trial-balance columns, closing
lines, and the rounding plug for member splits. It is generic over a
checked `Amount` trait. The engine runs it on Decimal (validate,
movements, reverse_entry, account_balance, close_period_to, allocate,
trial_balance): there is one copy of the arithmetic, and it is the one
under proof.

Three layers, docs/verification.md maps every law to its proofs:

- Kani (src/proofs.rs): 17 harnesses prove the kernel at i64 for every
  input up to 4 lines over 3 accounts. An entry is accepted exactly
  when it is two or more positive, in-range lines whose debits equal
  credits; accepted entries net to zero; grouping by account loses
  nothing; a reversal mirrors and cancels its original; trial-balance
  columns balance iff the books net to zero; closing lines zero their
  accounts and a close balances however the net is split; the plug
  makes parts sum to the whole. No panics, no overflow. kani::cover!
  shows the proofs are not vacuous.
- Lean 4 (verify/lean): 24 headline theorems for books of any size. The
  ledger is a state machine (add account, draft, post, reverse, open,
  close), and in every reachable state the books net to zero, the trial
  balance balances (as of any date), and the accounting equation holds.
  Posting only appends ("posted is forever"), closed periods are
  frozen, a close zeroes revenue and expenses and credits exactly the net
  income, and period statements add up. Audit.lean shows standard axioms
  only, no sorry.
- Bridge (tests/kernel_bridge.rs): the Decimal and i64 kernels agree.

What the proofs found (each one missed by every test, fuzzer, and
mutant):

- The engine accepted negative line amounts; only MCP refused them. Now
  NegativeAmountLine: direction is the side's job.
- Summing lines near Decimal::MAX panicked. Lines are now capped at one
  quadrillion and ten decimal places (AmountOutOfRange), which keeps
  every realistic sum exact, and the kernel's sums are checked.
- FX conversion (foreign_amount * fx_rate) could panic the same way; it
  is now a checked multiply.
- Kani itself: 0.68 mis-models symbolic-length copy_from_slice
  (model-checking/kani#4904) and reported a reversal that doesn't net to
  zero. The counterexample, replayed natively, passes, and a 15-line
  standalone crate reproduces the bug. Harnesses avoid bulk copies, and
  a should_panic canary will flag the upstream fix.

`just prove` runs it all (Kani memory- and time-capped, fails on an
unsatisfiable cover or a non-standard Lean axiom). AGENTS.md now makes
formal coverage part of every core change.

Also, docs: GnuCash is *an* oracle, never *the* oracle (the owner). The
spec is accounting principles, proved. Golden files are recomputed from
principles. External implementations (GnuCash, the old Sheet, QBO/Xero)
are cross-checks whose disagreements get adjudicated, never obeyed.
docs/oracle.md gains "Who is right"; AGENTS, README, architecture,
roadmap, parity, and STATUS are reworded to match.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
2026-10-13 11:12:13 -06:00