Avl_topo 
Topological sort of a graph.

Avl_tarjan 
Tarjan's algorithm: calculating SCC of a graph in linear time.

Avl_closure 
Transitive closure of a directed graph.

Avl_kernel 
Transitive reduction of a directed graph.

Avl_graphviz 
Interface with GraphViz

Avl_draw 
Drawing graphs.
