While studying discrete maths I was having difficult to understand the following definition:
Here is a definition about connected graphs from the book Ralph Grimaldi - Discrete and Combinatorial Mathematics - 5ed.
(from page 517)
What I can't understand is the second property/definition, the one that says, when you have a directed graph, then if the associated undirected graph is connected, that implies that the directed graph will be connected too.
I could easily draw an example when this doesn't occurs:
(2) is the undirected associated graph and IT'S CONNECTED.
But, I don't agree about that, I don't see how (1) can be connected too, because you don't have a path from d to a for example.