Correctness and Complexity of BMSSP in Isabelle/HOL

Arthur Freitas Ramos 📧, David Barros Hulak 📧 and Ruy Jose Guerra Barretto de Queiroz 📧

June 12, 2026

Abstract

This development formalizes the bounded multi-source shortest path (BMSSP) algorithm underlying the deterministic directed single-source shortest path algorithm of Duan, Mao, Mao, Shu, and Yin [2]. It proves three explicit claims. First, the executable bmssp_distances computes the exact reachable shortest-distance map for well-formed f inite natural weighted digraphs. Second, a separate costed BMSSP recurrence satisfies the O(mlog2/3 n) bound under the abstract In sert/BatchPrepend/Pull operation-cost interface. Third, the bucketed partition operations realize the primitive costs required by that interface. The formalization does not state a single generated-code machine-step theorem for the executable. The entry also exports executable SML and includes a checked worked shortest-path example whose evaluated output is [(0,0),(1,3),(2,5),(3,8),(4,6)]

License

BSD License

Note

Codex with gpt 5.5 on xhigh was used to help with proof engineering

Topics

Session BMSSP_Correctness