{"id":"financial-concurrency-is-comprehensively-safe","text":"Financial systems achieve comprehensive monetary safety when domain-appropriate concurrency strategies (pessimistic locking, optimistic version checks) and monotonic state ratchets (cursors that only advance, preconditions before removal) jointly prevent both concurrent corruption and state regression across all money-movement operations.","truth_value":"IN","source":"","source_url":"","source_hash":"","justifications":[{"type":"SL","antecedents":["concurrency-safety-strategy-varies-by-financial-risk","monotonicity-and-caution-prevent-state-loss"],"outlist":["payment-balance-check-not-atomic"],"label":"comprehensive financial safety requires both concurrency control and monotonic guards; the non-atomic payment balance check leaves a gap"}],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"financial-concurrency-is-comprehensively-safe","truth_value":"IN","reason":"SL justification valid","antecedents":["concurrency-safety-strategy-varies-by-financial-risk","monotonicity-and-caution-prevent-state-loss"],"label":"comprehensive financial safety requires both concurrency control and monotonic guards; the non-atomic payment balance check leaves a gap","outlist":["payment-balance-check-not-atomic"]},{"node":"concurrency-safety-strategy-varies-by-financial-risk","truth_value":"IN","reason":"SL justification valid","antecedents":["wallet-transfers-are-safe-under-concurrency","hotel-occ-prevents-overbooking"],"label":"Wallets can't tolerate any conflict window (money at risk); hotels can retry (inventory contention is less costly)"},{"node":"wallet-transfers-are-safe-under-concurrency","truth_value":"IN","reason":"SL justification valid","antecedents":["wallet-deadlock-free-concurrent-transfers"],"label":"sorted lock ordering prevents deadlock and frozen-check prevents TOCTOU, but `create_wallet` silently replacing an existing wallet could reset balance and lose in-flight transaction state for any concurrent transfer holding a lock on that wallet","outlist":["wallet-creation-silently-overwrites"]},{"node":"wallet-deadlock-free-concurrent-transfers","truth_value":"IN","reason":"SL justification valid","antecedents":["wallet-lock-ordering-prevents-deadlock","wallet-frozen-check-inside-lock","wallet-two-tier-locking"],"label":"Three complementary locking disciplines compose into a deadlock-free, race-free concurrency model"},{"node":"wallet-lock-ordering-prevents-deadlock","truth_value":"IN","reason":"premise"},{"node":"wallet-frozen-check-inside-lock","truth_value":"IN","reason":"premise"},{"node":"wallet-two-tier-locking","truth_value":"IN","reason":"premise"},{"node":"hotel-occ-prevents-overbooking","truth_value":"IN","reason":"SL justification valid","antecedents":["hotel-reservation-optimistic-locking","hotel-search-availability-is-bottleneck-date"],"label":"OCC prevents concurrent overbook, but negative inventory from cancel underflow corrupts the availability data that OCC is protecting","outlist":["hotel-cancel-no-underflow-guard"]},{"node":"hotel-reservation-optimistic-locking","truth_value":"IN","reason":"premise"},{"node":"hotel-search-availability-is-bottleneck-date","truth_value":"IN","reason":"premise"},{"node":"monotonicity-and-caution-prevent-state-loss","truth_value":"IN","reason":"SL justification valid","antecedents":["state-ratchets-prevent-regression-across-domains","deletion-is-guarded-by-preconditions"],"label":"Anti-regression ratchets and deletion preconditions cover modification and removal but not creation — silent overwrite on create is an unguarded state-loss vector","outlist":["wallet-creation-silently-overwrites"]},{"node":"state-ratchets-prevent-regression-across-domains","truth_value":"IN","reason":"SL justification valid","antecedents":["chat-monotonic-read-progress","watermark-finalization-is-irreversible"],"label":"chat read cursors are monotonic (never re-mark as unread), aggregation windows follow OPEN→CLOSED→FINALIZED with no reversal — both are state ratchets that make backwards movement structurally impossible"},{"node":"chat-monotonic-read-progress","truth_value":"IN","reason":"SL justification valid","antecedents":["chat-dual-ordering-sequence-and-lamport","chat-read-cursors-monotonic"],"label":"Sequence-number ordering + monotonic cursors create an irreversible read-progress guarantee"},{"node":"chat-dual-ordering-sequence-and-lamport","truth_value":"IN","reason":"premise"},{"node":"chat-read-cursors-monotonic","truth_value":"IN","reason":"premise"},{"node":"watermark-finalization-is-irreversible","truth_value":"IN","reason":"SL justification valid","antecedents":["watermark-drives-finalization","window-lifecycle-one-directional","no-window-merging-or-retraction"],"label":"Three properties compose into hard irreversibility: watermark-only trigger + one-way lifecycle + no retraction"},{"node":"watermark-drives-finalization","truth_value":"IN","reason":"premise"},{"node":"window-lifecycle-one-directional","truth_value":"IN","reason":"premise"},{"node":"no-window-merging-or-retraction","truth_value":"IN","reason":"premise"},{"node":"deletion-is-guarded-by-preconditions","truth_value":"IN","reason":"SL justification valid","antecedents":["s3-bucket-delete-requires-empty","email-service-two-phase-delete"],"label":"Both systems gate permanent deletion behind a prior state transition, making accidental data loss a two-mistake problem"},{"node":"s3-bucket-delete-requires-empty","truth_value":"IN","reason":"premise"},{"node":"email-service-two-phase-delete","truth_value":"IN","reason":"premise"}]}}