Subject: [Roll] Could all paths terminate at two nodes?

From: Alexandru Petrescu <[email-masked]>
Date: Sat, 24 Jul 2010 23:47:27 +0200

Could all paths terminate at two nodes?

> DAG:  Directed Acyclic Graph.  A directed graph having the property
>          that all edges are oriented in such a way that no cycles exist.
>          All edges are contained in paths oriented toward and
>          terminating at one or more root nodes.

For some reason I have a hard time understanding: "all [...] paths 
terminating at [...] more root nodes".

Is it possible to have _all_ unicast paths to _terminate_ at _two_ root 
nodes?  If they _all_ _terminate_ at one node then not even one could go 
any further to the second node.

Or is it that edges and paths are not the same thing?

Or is it that _some_ paths may terminate at a node whereas _other_ paths 
could terminate at other node?  If so then it should say so.  For example:

"All edges are contained in paths and all paths contain edges (define 
"contain").  Paths are oriented towards terminating nodes; some paths 
may terminate at  some nodes whereas other paths at other nodes".

(this definition has strong influence on understanding the subsequent 
definitions DAG root, DODAG root, and the rest of the draft and discussion).

Alex