摘要
本文对第(25)和第(50)类压缩型映象,C-映象和广义压缩映象等四类重要的映象,得出了不动点存在的几个充分必要条件.这些结果不仅改进和发展了〔1-3,5-7,9〕中的相应结果,而且也解答了 Rhoades〔7〕(亦见〔8〕)提出的一个未解决的问题.
Some sufficient and necessary conditions of existence of fixed pints for (25)and(50)type contractive mappings,C-mapping and generalized con- tractive mappings are obtained.The resulcs presented in this paper not only improve and extend the corresponding results of〔1-3,5-7,9〕but also answer an open question suggested by Rhoades〔7〕(see also〔8〕).
基金
国家自然科学基金资助课题
关键词
压缩映射
不动点
度量空间
contraction mapping
fixed point
sufficient
necessary condition
