## 5 Use Case
### Step-by-Step Use-Case Implementation  
This scenario illustrates how the BFS system can be used to facilitate and document various business and accounting transactions among these entities, demonstrating the BFS system's application in financial reporting, accounting, and liquidity management. The steps of this implementation are as follows:  
1. Entity A Incorporation: **Scenario:** Entity A is incorporated as a private company limited by shares. **Implementation:** The BFS system that belongs to Entity A is instantiated and contains the \"filing history chain of blocks\", a data structure inspired by the Bitcoin data structure [10]; the integrity of the data within the blocks is guaranteed by the integrity of the ledger itself [2]. In our proposed architecture, the BFS system records the incorporation details of Entity A, including the Certificate of Incorporation, in the genesis block of Entity A's BFS filing history blockchain, as illustrated in Figure 1. This block is uniquely identified by its hash, ensuring the integrity and authenticity of Entity A's foundational data. 2. Business Transaction 1--Share Purchase: **Scenario:** Entity B, as the parent of Entity A, purchases shares from Entity A and becomes the sole shareholder at incorporation. **Implementation:** The BFS system documents the shareholding structure, linking Entity B's wallet to Entity A's blockchain, as illustrated in Figure 4 and described further. The BFS system processes this transaction using a BFS business transaction smart contract and tokenised shares in accordance with Corda's _Flow Framework_[11], which provides point-to-point data broadcast only to the counterparties of the business transaction. The BFS business transaction smart contract automates the transfer of share certificate tokens from Entity A's ownership through Entity A's director wallet to Entity B's shareholder wallet in exchange for digital funds that are simultaneously transferred from Entity B to Entity A. The successfully completed transaction is then recorded in the business transaction registers of Entity A's BFS and Entity B's BFS, respectively, in accordance with Corda's _Transaction Vault_[11]. This flow is illustrated in Figure 2.
3. First Accounting Transaction: **Scenario:** Entity A records its first accounting transaction related to the share purchase. **Implementation:** The accountant of Entity A initiates the first accounting transaction smart contract, which automates the BFS accounting cycle; this is illustrated in Figure 5. BFS accounting smart contracts transform economic data generated by the first business transaction into accounting data and post this accounting data into the accounting journals and ledgers of the BFS system that belongs to Entity A. Final financial statements are automatically generated and appended to the BFS filing history blockchain, ensuring the accuracy and transparency of Entity A's financial reporting data. These final financial statements are published in the Bitcoin-inspired data structure of Entity A's BFS filing history block, as illustrated in Figure 1.
4. Business Transaction 2-Four-Party Atomic Swap of Treasury Bills for Commercial Paper:  
**Scenario:** Entity A begins its economic activity, where part of its business objective is to purchase commercial paper from Entity C, and Entity C requires payment in Treasury bills in exchange for commercial paper. Entity A does not hold Treasury bills but its parent company, Entity B, does. Entity A requests Treasury bills from Entity B to enable the purchase of commercial paper from Entity C. Subsequently, Entity B lends Treasury bills to Entity A, which then uses them to purchase commercial paper from Entity C.  
**Implementation:** The BFS system executes this four-party atomic swap using BFS smart contracts. _Step 1:_ Entity B transfers Treasury bills to Entity A. This transaction is executed by two parties: the lender wallet of Entity B and the borrower wallet of Entity A. _Step 2:_ Entity A transfers the Treasury bills to Entity C in exchange for commercial paper.