collapsible,contractible是什么意思

用法例句

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.

研究图X与一簇图 { Yx x∈V(X) }的广义字典序积X〔Yx x∈V(X)〕的自同态幺半群 ,得到当所有Yx 的团数都相等时 ,C2n + 1〔Yx x∈V(C2n + 1)〕是不可收缩的当且仅当每一个Yx 是不可收缩

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

h-连通图中可收缩边的存在定理

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

某些5-连通图中最长圈上的可收缩边

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连通图中任意两个相邻顶点的度的和至少是25k/4-1,则图中有k-可收缩边。