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arXiv · 2512.07766

Formalized Hopfield Networks and Boltzmann Machines

Abstract

Neural networks are widely used, yet their analysis and verification remain challenging. We present a Lean~4 formalization covering both deterministic and stochastic models. We first formalize Hopfield networks -- recurrent networks that store patterns as stable states -- and prove their convergence, and the correctness of Hebbian learning, the rule that updates parameters to encode patterns. We then turn to stochastic networks, whose probabilistic updates converge to a stationary distribution: we formalize the dynamics and learning of Boltzmann machines and prove their ergodicity -- convergence to a \emph{unique} stationary distribution -- via a new formalization of the Perron--Frobenius theorem.

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Matteo Cipollina, Michail Karatarakis, Freek Wiedijk. 2026-09-15. Formalized Hopfield Networks and Boltzmann Machines. https://arxiv.org/abs/2512.07766

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