A function defined on a topological space is called returning if for any point there exists a positive real number such that for every path-connected subset containing the point and any there exists a point $z\in C_x\setminus{x,y}|f(z)|\le \max{M_x,|f(y)|}$. A topological space is called path-inductive if a subset is open if and only if for any path the preimage is open in . The class of path-inductive spaces includes all first-countable locally path-connected spaces and all sequential locally contractible space. We prove that a function defined on a path-inductive space is continuous if and only of it is returning and has closed graph. This implies that a (weakly) 'Swi\c atkowski function is continuous if and only if it has closed graph, which answers a problem of Maliszewski, inscibed to Lviv Scottish Book.

生成讲解博客的中文版本

生成AI智能校验的中文版本