Formal Verification of Minimax Algorithms

ArXi:2509.20138v2 Announce Type: replace Minimax-based search algorithms with alpha-beta pruning and transposition tables are a central component of classical game-playing engines and remain widely used in practice. Despite their widespread use, these algorithms are subtle, highly optimized, and notoriously difficult to reason about, making non-obvious errors hard to detect by testing alone. Using the Dafny verification system, we formally verify a range of minimax search algorithms, including variants with alpha-beta pruning and transposition tables.