go/src/internal/dag/alg.go

// Transpose reverses all edges in g.
func (g *Graph) Transpose() { … }

// Topo returns a topological sort of g. This function is deterministic.
func (g *Graph) Topo() []string { … }

// TransitiveReduction removes edges from g that are transitively
// reachable. g must be transitively closed.
func (g *Graph) TransitiveReduction() { … }