长春工业大学学报（自然科学版）
長春工業大學學報（自然科學版）
장춘공업대학학보（자연과학판）
Journal of Changchun University of Technology(Natural Science Edition)
2015年
4期
470-472
,共3页
平面图%分离圈%延拓性定理
平麵圖%分離圈%延拓性定理
평면도%분리권%연탁성정리
planar graph%separating cycles%extension theorem
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.
根據每箇不包含{4,5,6,7}-圈的平麵圖是3-可染的性質 ,證明不包含{4,5,7}-圈的平麵圖中不含分離的6-圈、不含內部的6-麵及|f0|≠6,從而證明瞭不包含{4,5,7}-圈的平麵圖是3-可染的延拓性定理.
근거매개불포함{4,5,6,7}-권적평면도시3-가염적성질 ,증명불포함{4,5,7}-권적평면도중불함분리적6-권、불함내부적6-면급|f0|≠6,종이증명료불포함{4,5,7}-권적평면도시3-가염적연탁성정리.
According to the theorem that planar graph without 4 and 5 ,6 ,7-cycles is 3-colorable ,we prove that a planar graph without 4 and 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 .
