Arborescence: различия между версиями

'''Arborescence''' — ''[[ориентированное дерево]].''  

This is a [[digraph]] <math>\,G</math> with a specified [[vertex]] <math>\,a</math> called a ''[[root]]'' such that each ''[[point]]'' <math>x\neq a</math> has [[indegree]] 1 and there is a unique <math>\,(a,x)</math>-path for each point <math>\,x</math>.

'''Arborescence''' can be obtained by specifying a [[vertex]] <math>\,a</math> of a [[tree]]

and  then orienting each [[edge]] <math>\,e</math> such that the unique [[path]] connecting

<math>\,a</math> to <math>\,e</math> ends at the tail of <math>\,e</math>. An '''[[inverse arborescence]]''' is a digraph obtained from an '''arborescence''' by inverting its edges.