
Briefing
The core research problem is the systemic impact of Maximal Extractable Value (MEV) on decentralized applications, where the vast and complex space of adversarial strategies renders traditional empirical analysis and pen-and-paper proofs insufficient for guaranteeing security bounds. This paper introduces the first mechanized formalization of MEV within the Lean theorem prover, establishing a methodology to construct machine-checked proofs of MEV bounds that rigorously determine the maximum extractable value for a given protocol. This breakthrough provides a foundation for provably secure and MEV-resilient protocol design, shifting the paradigm from heuristic mitigation to cryptographic-grade correctness guarantees for decentralized finance architectures.

Context
The foundational challenge in MEV research is the difficulty of rigorously bounding the value an adversary can extract by manipulating transaction ordering, inclusion, or exclusion. Prior to this work, the space of adversarial strategies was considered too expansive for comprehensive manual analysis, leading to reliance on empirical studies and informal reasoning. This created a critical security vulnerability ∞ without a formal upper bound, protocol designers could not definitively prove the absence of a novel, high-value MEV attack, undermining the foundational security assumptions of decentralized finance primitives.

Analysis
The paper’s core mechanism is the application of the Lean theorem prover, a formal verification tool, to model the state transitions and incentive landscape of DeFi protocols. The methodology involves translating the protocol’s logic and the adversary’s capabilities into a machine-readable mathematical framework. This framework allows researchers to construct and verify formal proofs about the system’s behavior, including proofs of MEV optimality.
The fundamental difference from previous approaches is the transition from a probabilistic or empirical understanding of MEV to a deterministic, logically certified one. By formally modeling the interaction between user transactions and the protocol’s state, the system can prove, with the highest degree of mathematical certainty, the exact upper limit of value an attacker can extract under a given set of constraints.

Parameters
- First Machine-Checked Proof ∞ The paper delivers the first machine-checked proof of the optimality of sandwich attacks in Automated Market Makers.
- Lean Theorem Prover ∞ The specific formal verification tool utilized to mechanize the MEV analysis and construct the machine-checked proofs.

Outlook
The immediate next step for this research is the expansion of the formal MEV framework to a broader range of complex DeFi primitives, including lending protocols and options markets. Strategically, this work lays the groundwork for a new generation of provably secure smart contracts. Within 3-5 years, this methodology could become a mandatory component of the audit process for high-value decentralized applications, enabling protocol designers to formally verify that their mechanisms are MEV-resistant by design. This opens a new avenue of research focused on using formal methods not just for bug-finding, but for proving the economic security properties of incentive-driven decentralized systems.
