### 4.3.4. The database of graph invariants

For each combination of graph parameters we give the number of graph invariants we currently have. The items are sorted first in increasing number of graph parameters of the invariant, second in alphabetic order on the name of the parameters. All graph invariants assume a digraph for which each vertex has at least one arc. For some propositions, a figure depicts the corresponding final graph, which minimises or maximises a given graph parameter. The propositions of this section and their corresponding proofs use the notations introduced in Section 2.3.2.4.1 on page 2.3.2.4.1.