Files
wanderbooks/verify/lean/Audit.lean
T
swaits 62f2fb058e feat(verify): prove a write-off never takes a document below zero (P4b S7)
Ledger::write_off is a new command, so it is a new Step: Step.writeOff,
whose two lines are a tagged control line (the receivable falls) and an
untagged expense line (the deduction). Being a document step in shape, it
moves nothing unattached, so control_agrees and
Reachable.control_is_documents still hold with no new proof:
Step.writeOff_unattached states its half of that.

writeOff_within_bounds is the law the command's refusal enforces: a
write-off of at most what the document is owed, read over the date-sum
docSum ... through D (B-38 fixed that sum, not standing), leaves what is
owed through the write-off's day at or above zero. through_append lets
the write-off's own two lines be read separately.

Both are listed in Audit.lean; just prove holds (standard axioms only, no
sorry).
2026-10-27 12:44:45 -06:00

101 lines
3.6 KiB
Lean4

import Wanderbooks
/-! `just prove` runs this file: each headline theorem's axioms are printed,
and must be only Lean's standard three (`propext`, `Quot.sound`,
`Classical.choice`) or fewer. No `sorryAx`, nothing assumed. -/
open Wanderbooks
#print axioms Accepted.net_zero
#print axioms sum_movements
#print axioms movement_with_reversal
#print axioms accepted_reversal_iff
#print axioms accounting_equation
#print axioms balance_after_line
#print axioms trial_balance_iff
#print axioms closingEntry_net
#print axioms closingEntry_zeroes
#print axioms closingEntry_accepted
#print axioms net_closings_is_net_income
#print axioms plugLast_total
#print axioms plugLast_keeps
#print axioms runPart_telescopes
#print axioms closePart_total
#print axioms trueUp_total
#print axioms trueUp_running
#print axioms closePart_eq_trueUp
#print axioms cumulative_drift
#print axioms statement_after_close
#print axioms statement_unmoved_by_close
#print axioms Reachable.inv
#print axioms Reachable.books_net_zero
#print axioms Reachable.trial_balance
#print axioms Reachable.trial_balance_through
#print axioms Reachable.accounting_equation
#print axioms Reachable.accounting_equation_through
#print axioms Steps.extends
#print axioms Steps.frozen
#print axioms close_zeroes
#print axioms close_credits_net_income
#print axioms statements_add_up
#print axioms Apportion.ranks_perm
#print axioms Apportion.apportion_sum
#print axioms Apportion.apportion_sum_of_shortfall
#print axioms Apportion.rem_pos_of_rank_lt
#print axioms Apportion.apportion_drift
#print axioms Apportion.allocW_sum
#print axioms Apportion.allocW_drift
#print axioms Apportion.allocW_cumulative_drift
#print axioms Apportion.allocW_cumulative_total
#print axioms Step.record_changes_no_figure
#print axioms Reachable.records
#print axioms net_splits_by_flow
#print axioms applyCash_conserves
#print axioms applyCash_exhausts
#print axioms applyCash_neg
#print axioms entry_flows_sum
#print axioms flows_reversal
#print axioms constructive_nets
#print axioms constructive_neg
#print axioms constructive_sections_net
#print axioms stmt_flows_sum
#print axioms stmt_flows_reversal
#print axioms cashflow_sections_sum_to_cash_change
#print axioms secNet_cash_is_movement
#print axioms operating_reconciliation_ties
#print axioms operating_reconciliation_ties_all
#print axioms cashflow_reversal_nets
#print axioms Reachable.cashflow_foots
#print axioms Reachable.cashflow_is_change_in_cash
#print axioms reverseTarget_involutive
#print axioms capitalTarget_odd
#print axioms partyTarget_odd
#print axioms sumOver_movement_reversal
#print axioms Prorate.cum_mono
#print axioms Prorate.cum_le
#print axioms Prorate.cum_full
#print axioms Prorate.parts_telescope
#print axioms Prorate.prorate_total
#print axioms Prorate.prorate_nonneg
#print axioms Prorate.part_within_a_unit
#print axioms Prorate.roundUnit_near
#print axioms Prorate.roundUnit_scale
#print axioms Prorate.cum_near
#print axioms Prorate.cum_dvd
#print axioms Prorate.part_near
#print axioms Prorate.chargeMid_eq_cum
#print axioms Prorate.chargeLast_eq_cum
#print axioms Prorate.chargeLast_start
#print axioms Prorate.chargeLast_mono
#print axioms Prorate.kernel_parts_total
#print axioms Prorate.kernel_parts_nonneg
#print axioms Documents.control_agrees
#print axioms Documents.control_agrees_through
#print axioms Documents.Step.document_unattached
#print axioms Documents.Step.reverse_moves
#print axioms Documents.reverse_twice
#print axioms Documents.Reachable.unattached_zero
#print axioms Documents.Reachable.control_is_documents
#print axioms Documents.Step.writeOff_unattached
#print axioms Documents.writeOff_within_bounds