[{"issue":"4","_id":"1682","publication_status":"published","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 &gt; 0, it holds that each function g: K → ℝn such that ||g - f || ∞ &lt; 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 &gt; 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."}],"arxiv":1,"main_file_link":[{"url":"http://arxiv.org/abs/1402.0858","open_access":"1"}],"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","scopus_import":"1","doi":"10.1145/2751524","month":"08","oa_version":"Preprint","oa":1,"isi":1,"year":"2015","title":"Robust satisfiability of systems of equations","volume":62,"publication":"Journal of the ACM","date_published":"2015-08-01T00:00:00Z","quality_controlled":"1","publist_id":"5466","date_updated":"2025-09-23T10:38:46Z","citation":{"short":"P. Franek, M. Krcál, Journal of the ACM 62 (2015).","mla":"Franek, Peter, and Marek Krcál. “Robust Satisfiability of Systems of Equations.” <i>Journal of the ACM</i>, vol. 62, no. 4, 26, ACM, 2015, doi:<a href=\"https://doi.org/10.1145/2751524\">10.1145/2751524</a>.","apa":"Franek, P., &#38; Krcál, M. (2015). Robust satisfiability of systems of equations. <i>Journal of the ACM</i>. ACM. <a href=\"https://doi.org/10.1145/2751524\">https://doi.org/10.1145/2751524</a>","chicago":"Franek, Peter, and Marek Krcál. “Robust Satisfiability of Systems of Equations.” <i>Journal of the ACM</i>. ACM, 2015. <a href=\"https://doi.org/10.1145/2751524\">https://doi.org/10.1145/2751524</a>.","ieee":"P. Franek and M. Krcál, “Robust satisfiability of systems of equations,” <i>Journal of the ACM</i>, vol. 62, no. 4. ACM, 2015.","ista":"Franek P, Krcál M. 2015. Robust satisfiability of systems of equations. Journal of the ACM. 62(4), 26.","ama":"Franek P, Krcál M. Robust satisfiability of systems of equations. <i>Journal of the ACM</i>. 2015;62(4). doi:<a href=\"https://doi.org/10.1145/2751524\">10.1145/2751524</a>"},"intvolume":"        62","language":[{"iso":"eng"}],"type":"journal_article","author":[{"full_name":"Franek, Peter","first_name":"Peter","last_name":"Franek"},{"full_name":"Krcál, Marek","id":"33E21118-F248-11E8-B48F-1D18A9856A87","last_name":"Krcál","first_name":"Marek"}],"external_id":{"isi":["000361200500001"],"arxiv":["1402.0858"]},"publisher":"ACM","corr_author":"1","date_created":"2018-12-11T11:53:27Z","department":[{"_id":"UlWa"},{"_id":"HeEd"}],"article_processing_charge":"No","status":"public","day":"01","article_number":"26"}]