Complexity of the consistency problem for systems of Diophantine equations over finite bipartite graphs

Complexity of the consistency problem for systems of Diophantine equations over finite bipartite graphs

(Russian, English abstract)

Kobzev F. D., Kogabaev N. T.
Siberian Electronic Mathematical Reports, 23, 1, pp. 266-288 (2026)

УДК 510.522, 519.178 
DOI: 10.33048/semi.2026.23.017  
MSC 03D15, 05C85


Abstract:

We study finite systems of Diophantine equations over finite bipartite graphs. In 2021, A.V. Il'ev and V.P. Il'ev proposed a deterministic polynomial-time procedure for verifying the consistency of such systems. We construct a counterexample to show that their procedure works incorrectly and prove that the consistency problem for such systems is in fact NP-complete.

Keywords: bipartite graph, system of equations, nondeterministic Turing machine, NP-complete problem