Common Prefix is formally verifying the $XRP Ledger Lending Protocol to mathematically prove that it cannot be drained, become insolvent, or break its rules. The work focuses on the Lending Protocol introduced through XLS-66. Common Prefix explained its approach in a six-part series, including why it chose Lean 4 for the verification process. Common Prefix said formal verification goes beyond normal software testing by using mathematics to prove that a system works correctly in all possible situations. XRP Ledger validator Vet, also known as Hussein Zangana, said formal verification is already used in high-risk systems such as military technology, air traffic software, flight controls, and nuclear power plants. He explained that the approach uses mathematics to show a system remains valid across all possible inputs, not just the situations developers have tested. Common Prefix considered several tools, including Dafny, Lean 4, TLA+, and P. The team decided that TLA+ and P were not a good fit for the specific questions it needed to answer about the lending protocol. One reason it chose Lean 4 was that it does not rely on an SMT solver. Common Prefix found that Dafny’s solver could sometimes time out when handling the complex arithmetic needed for the verification. Lean requires more work by hand, but this also makes errors easier for developers to find and fix. #Ripple https://t.co/s0YcQ4KAWX