How did Anthropic’s Claude AI prove Fermat’s Last Theorem with 13 million lines of code?

Anthropic’s Claude AI successfully translated Fermat’s Last Theorem into 13 million lines of formal, computer-verifiable code over an 11-day period. This breakthrough demonstrates that AI can now automate formal verification, a process essential for securing high-stakes blockchain protocols and smart contracts against exploits.
How did Anthropic’s Claude AI prove Fermat’s Last Theorem with 13 million lines of code?

Anthropic’s Claude AI model has solved a 350-year-old mathematical challenge by translating Fermat’s Last Theorem into 13 million lines of code that a computer can independently verify. Using the formal proof language Lean, the AI spent 11 days constructing a logic chain that requires no human trust to validate. This represents the longest proof ever recorded and proves that Large Language Models (LLMs) are becoming capable of rigorous, deterministic reasoning rather than just probabilistic text generation.

For the cryptocurrency and decentralized finance (DeFi) sectors, this achievement is a significant technical milestone. The primary cause of multi-million dollar hacks in the crypto space is human error within smart contract code. Claude’s ability to generate massive, machine-verifiable proofs suggests a future where blockchain developers can use AI to mathematically guarantee that a protocol is free of bugs or logical vulnerabilities before deployment.

In the United States, where regulatory bodies like the SEC and CFTC are increasingly focused on consumer protection and platform security, the adoption of AI-driven formal verification could become a compliance standard. As institutional investors demand higher security benchmarks, tools that provide mathematical certainty of code integrity will likely become central to the Web3 development stack.

Moving forward, market participants should watch for the integration of Anthropic’s models into automated auditing suites. The ability to verify complex logic at this scale could significantly lower the cost of security audits and accelerate the launch of more complex DeFi products. While this specific feat is mathematical, its application in cryptographic security is the next logical step for AI development.