{"title":"可行闭包性质的复杂性理论","authors":"M. Ogiwara, L. Hemachandra","doi":"10.1109/SCT.1991.160240","DOIUrl":null,"url":null,"abstract":"The authors propose and develop a complexity theory of feasible closure properties. For each of the classes Hash P, SpanP, OptP, and MidP, they establish complete characterizations-in terms of complexity class collapses-of the conditions under which the class has all feasible closure properties. In particular, Hash P is P-closed if and only if PP=UP; SpanP is P-closed if and only if R-MidP is P-closed if and only if P/sup PP/=NP; and OptP is P-closed if and only if NP=co-NP. Furthermore, for each of these classes, the authors show natural operations-such as subtraction and division-to be hard closure properties, in the sense that if a class is closed under one of these, then it has all feasible closure properties. They also study potentially intermediate closure properties for Hash P. These properties-maximum, minimum, median, and decrement-seem neither to be possessed by Hash P nor to be Hash P-hard.<<ETX>>","PeriodicalId":158682,"journal":{"name":"[1991] Proceedings of the Sixth Annual Structure in Complexity Theory Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"1991-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"41","resultStr":"{\"title\":\"A complexity theory for feasible closure properties\",\"authors\":\"M. Ogiwara, L. Hemachandra\",\"doi\":\"10.1109/SCT.1991.160240\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The authors propose and develop a complexity theory of feasible closure properties. For each of the classes Hash P, SpanP, OptP, and MidP, they establish complete characterizations-in terms of complexity class collapses-of the conditions under which the class has all feasible closure properties. In particular, Hash P is P-closed if and only if PP=UP; SpanP is P-closed if and only if R-MidP is P-closed if and only if P/sup PP/=NP; and OptP is P-closed if and only if NP=co-NP. Furthermore, for each of these classes, the authors show natural operations-such as subtraction and division-to be hard closure properties, in the sense that if a class is closed under one of these, then it has all feasible closure properties. They also study potentially intermediate closure properties for Hash P. These properties-maximum, minimum, median, and decrement-seem neither to be possessed by Hash P nor to be Hash P-hard.<<ETX>>\",\"PeriodicalId\":158682,\"journal\":{\"name\":\"[1991] Proceedings of the Sixth Annual Structure in Complexity Theory Conference\",\"volume\":\"16 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1991-06-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"41\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"[1991] Proceedings of the Sixth Annual Structure in Complexity Theory Conference\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1109/SCT.1991.160240\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"[1991] Proceedings of the Sixth Annual Structure in Complexity Theory Conference","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/SCT.1991.160240","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
A complexity theory for feasible closure properties
The authors propose and develop a complexity theory of feasible closure properties. For each of the classes Hash P, SpanP, OptP, and MidP, they establish complete characterizations-in terms of complexity class collapses-of the conditions under which the class has all feasible closure properties. In particular, Hash P is P-closed if and only if PP=UP; SpanP is P-closed if and only if R-MidP is P-closed if and only if P/sup PP/=NP; and OptP is P-closed if and only if NP=co-NP. Furthermore, for each of these classes, the authors show natural operations-such as subtraction and division-to be hard closure properties, in the sense that if a class is closed under one of these, then it has all feasible closure properties. They also study potentially intermediate closure properties for Hash P. These properties-maximum, minimum, median, and decrement-seem neither to be possessed by Hash P nor to be Hash P-hard.<>