collapsible,contractible

If the clique numbers of all graphs Y x are the same,C 2n+1 〔Y xx∈V( C 2n+1 )〕 is unretractive if and only if every Y x is unretractive.

研究圖X與一簇圖 { Yx x∈V(X) }的廣義字典序積X〔Yx x∈V(X)〕的自同態幺半群 ,得到當所有Yx 的團數都相等時 ,C2n + 1〔Yx x∈V(C2n + 1)〕是不可收縮的當且僅當每一個Yx 是不可收縮

The existence theorem of contractible edges in h-connected graphs;

h-連通圖中可收縮邊的存在定理

The contractible edges of the longest cycle in some 5-connected graphs;

某些5-連通圖中最長圈上的可收縮邊

Kriesell conjectured that every K, connected graph has a k-contractible edge if the degree sum of any two adjacent vertices is at least 2 5k/4- 1.

Kriesell(2001年)猜想:如果k連通圖中任意兩個相鄰頂點的度的和至少是25k/4-1,則圖中有k-可收縮邊。