{"title":"在F-spaces","authors":"Sheldon W. Davis","doi":"10.1016/0016-660X(78)90058-2","DOIUrl":null,"url":null,"abstract":"<div><p>We present the class of <span><math><mtext>F</mtext></math></span><sub>t</sub>-spaces which is a subclass of the class of <span><math><mtext>F</mtext></math></span>-spaces of Harley and Stephenson containing many of the most interesting <span><math><mtext>F</mtext></math></span>-spaces, e.g. the Michael line, the Sorgenfrey line, Aleksandrov's double interval.</p><p>We prove that the <span><math><mtext>F</mtext></math></span><sub>t</sub>-spaces satisfy certain covering properties which <span><math><mtext>F</mtext></math></span>-spaces need not satisfy. In particular, (1) every neighborhood <span><math><mtext>F</mtext></math></span><sub>t</sub>-space is subparacompact, and (2) every <span><math><mtext>F</mtext></math></span><sub>t</sub>-space satisfies property L of Bacon. On the other hand, there are examples of neighborhood <span><math><mtext>F</mtext></math></span>-spaces which do not satisfy L.</p></div>","PeriodicalId":100574,"journal":{"name":"General Topology and its Applications","volume":"9 2","pages":"Pages 131-138"},"PeriodicalIF":0.0000,"publicationDate":"1978-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0016-660X(78)90058-2","citationCount":"2","resultStr":"{\"title\":\"On F-spaces\",\"authors\":\"Sheldon W. Davis\",\"doi\":\"10.1016/0016-660X(78)90058-2\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We present the class of <span><math><mtext>F</mtext></math></span><sub>t</sub>-spaces which is a subclass of the class of <span><math><mtext>F</mtext></math></span>-spaces of Harley and Stephenson containing many of the most interesting <span><math><mtext>F</mtext></math></span>-spaces, e.g. the Michael line, the Sorgenfrey line, Aleksandrov's double interval.</p><p>We prove that the <span><math><mtext>F</mtext></math></span><sub>t</sub>-spaces satisfy certain covering properties which <span><math><mtext>F</mtext></math></span>-spaces need not satisfy. In particular, (1) every neighborhood <span><math><mtext>F</mtext></math></span><sub>t</sub>-space is subparacompact, and (2) every <span><math><mtext>F</mtext></math></span><sub>t</sub>-space satisfies property L of Bacon. On the other hand, there are examples of neighborhood <span><math><mtext>F</mtext></math></span>-spaces which do not satisfy L.</p></div>\",\"PeriodicalId\":100574,\"journal\":{\"name\":\"General Topology and its Applications\",\"volume\":\"9 2\",\"pages\":\"Pages 131-138\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1978-07-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/0016-660X(78)90058-2\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"General Topology and its Applications\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/0016660X78900582\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"General Topology and its Applications","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/0016660X78900582","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
We present the class of t-spaces which is a subclass of the class of -spaces of Harley and Stephenson containing many of the most interesting -spaces, e.g. the Michael line, the Sorgenfrey line, Aleksandrov's double interval.
We prove that the t-spaces satisfy certain covering properties which -spaces need not satisfy. In particular, (1) every neighborhood t-space is subparacompact, and (2) every t-space satisfies property L of Bacon. On the other hand, there are examples of neighborhood -spaces which do not satisfy L.