IsConnectedGraph( gamma )
This boolean function returns true
if and only if gamma is (strongly)
connected, i.e. if there is a (directed) path from x to y for every
pair of vertices x,y of gamma.
gap> IsConnectedGraph( JohnsonGraph(4,2) ); true gap> IsConnectedGraph( NullGraph(SymmetricGroup(4)) ); false
GAP 3.4.4