不包含{4,5,7}圈的平面图是3-可染的延拓性定理  

3-colorability extension theorem without{4,5,7}-cycle planar graph

作　　者：方冬云[1] 

机构地区：[1]莆田学院数学学院,福建莆田351100

出　　处：《长春工业大学学报》2015年第4期470-472,共3页Journal of Changchun University of Technology

基　　金：福建省高校服务海西项目(2008HX03);福建省教育厅A类项目(JA12245S)

摘　　要：根据每个不包含{4,5,6,7}-圈的平面图是3-可染的性质,证明不包含{4,5,7}-圈的平面图中不含分离的6-圈、不含内部的6-面及|f0|≠6,从而证明了不包含{4,5,7}-圈的平面图是3-可染的延拓性定理。According to the theorem that planar graph without 4and 5,6,7-cycles is 3-colorable,we prove that a planar graph without 4and 5,7-cycles does not contain separating 6-cycles,internal 6-faces and｜f0｜≠6.Consequently,the extension theorem is proved that a plane graph without{4,5,7}cycles is 3-colorable.

关 键 词：平面图 分离圈 延拓性定理 

分 类 号：O157.5[理学—数学]