The matrix is n by n, where n is the number of vertices in the graph. The entry (i, j) is one if there exists an arc (directed) that links from i to j.

Positive 1: Out coming edges from each vertices. * Column sum is always zero. * Always a negative&positive one in each column. * The matrix is M by N, where N is the number of vertices and the N is the number of edges.

Unbouded complex sequence have their differences in l-inf that is unbounded too, which breaks the definitions of a metric.

$$ \sup_{i\in \mathbb N} |x_i - y_i| \not < \infty $$

a district of a city or town as defined for police purposes.

Just an annotations to see how this thing works.