However for other graphs these two quantities may differ.
In contrast to the situation for graphs, almost all trees are symmetric.
Include color for your charts and graphs if you can.
It is known to be true for cubic graphs.
There are 314 principles for good graphs and charts.
For certain graphs, even fewer than Δ colors may be needed.
However, this conjecture remains open for graphs that need not be cubic.
Versions of these definitions are also used for directed graphs.
The conjecture has since been proven for graphs of maximum degree seven.
It is also possible to define Ramsey numbers for "directed" graphs.