{"author":[{"full_name":"Franek, Peter","last_name":"Franek","first_name":"Peter"},{"full_name":"Krcál, Marek","first_name":"Marek","last_name":"Krcál","id":"33E21118-F248-11E8-B48F-1D18A9856A87"}],"date_updated":"2021-01-12T06:52:30Z","language":[{"iso":"eng"}],"date_created":"2018-12-11T11:53:27Z","title":"Robust satisfiability of systems of equations","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","issue":"4","_id":"1682","day":"01","year":"2015","quality_controlled":"1","doi":"10.1145/2751524","intvolume":" 62","publist_id":"5466","type":"journal_article","publication_status":"published","scopus_import":1,"article_number":"26","main_file_link":[{"open_access":"1","url":"http://arxiv.org/abs/1402.0858"}],"volume":62,"publisher":"ACM","citation":{"ieee":"P. Franek and M. Krcál, “Robust satisfiability of systems of equations,” Journal of the ACM, vol. 62, no. 4. ACM, 2015.","short":"P. Franek, M. Krcál, Journal of the ACM 62 (2015).","apa":"Franek, P., & Krcál, M. (2015). Robust satisfiability of systems of equations. Journal of the ACM. ACM. https://doi.org/10.1145/2751524","chicago":"Franek, Peter, and Marek Krcál. “Robust Satisfiability of Systems of Equations.” Journal of the ACM. ACM, 2015. https://doi.org/10.1145/2751524.","ama":"Franek P, Krcál M. Robust satisfiability of systems of equations. Journal of the ACM. 2015;62(4). doi:10.1145/2751524","mla":"Franek, Peter, and Marek Krcál. “Robust Satisfiability of Systems of Equations.” Journal of the ACM, vol. 62, no. 4, 26, ACM, 2015, doi:10.1145/2751524.","ista":"Franek P, Krcál M. 2015. Robust satisfiability of systems of equations. Journal of the ACM. 62(4), 26."},"publication":"Journal of the ACM","month":"08","department":[{"_id":"UlWa"},{"_id":"HeEd"}],"abstract":[{"lang":"eng","text":"We study the problem of robust satisfiability of systems of nonlinear equations, namely, whether for a given continuous function f:K→ ℝn on a finite simplicial complex K and α > 0, it holds that each function g: K → ℝn such that ||g - f || ∞ < α, has a root in K. Via a reduction to the extension problem of maps into a sphere, we particularly show that this problem is decidable in polynomial time for every fixed n, assuming dimK ≤ 2n - 3. This is a substantial extension of previous computational applications of topological degree and related concepts in numerical and interval analysis. Via a reverse reduction, we prove that the problem is undecidable when dim K > 2n - 2, where the threshold comes from the stable range in homotopy theory. For the lucidity of our exposition, we focus on the setting when f is simplexwise linear. Such functions can approximate general continuous functions, and thus we get approximation schemes and undecidability of the robust satisfiability in other possible settings."}],"oa":1,"status":"public","oa_version":"Preprint","date_published":"2015-08-01T00:00:00Z"}