University of Tabriz Computational Methods for Differential Equations 2345-3982 14 1 2026 11 01 A reproducing kernel method for solving nonlocal functional differential equations with delayed or advanced arguments 1 13 19399 10.22034/cmde.2025.63743.2850 EN Hajar Rasekhinezhad Department of Mathematics, Science and Research Branch, Islamic Azad University, Tehran, Iran. Saeid Abbasbandy Department of Applied Mathematics, Faculty of Science, Imam Khomeini International University, Qazvin, Iran. Tofigh Allahviranloo Faculty of Engineering and Natural Sciences, Istinye University, Istanbul, Turkey. Esmail Babolian Department of Computer Science, Faculty of Mathematical Sciences and Computer, Kharazmi University, Tehran, Iran. Journal Article 2024 09 28 This paper discusses an effective approach for solving non-local functional differential equations with delayed or advanced arguments. The reproducing kernel method is utilized to avoid the need for an orthogonalization process. The main objective of this technique is to successfully apply this method to solve singular multi-point boundary value problems with non-local conditions, resulting in an accurate approximate solution and a valid error analysis. This method greatly improves the accuracy of the solutions obtained. https://cmde.tabrizu.ac.ir/article_19399_a9f44f4c64489380638066684c4820cc.pdf