Status: IN
The double-entry ledger invariant (every movement creates balanced debit-credit pairs) and full-ledger balance derivation guarantee that balances reflect the true sum of all operations — unless the non-atomic overdraft check allows concurrent payments to both pass validation and create conflicting ledger entries.
Double-entry provides an audit invariant, but TOCTOU in the overdraft check can create entries that individually balance but collectively overdraw
Depends on (SL): double-entry-invariant, balance-derived-from-ledger
Unless: payment-overdraft-not-atomic