Topological order of directed acyclic graph

returns the topological order of the
nodes in `n`

= toposort(`G`

)`G`

such that `i < j`

for every edge
`(n(i),n(j))`

in `G`

. The directed graph
`G`

cannot have any cycles.

`digraph`

| `isdag`

| `reordernodes`