lRosalind B. Marimont
A new method of checking the consistency of precedence
matrices
Journal of the ACM 6, 164-171,
1959
lPruning away any arcs
that point to leaves does not change the
cyclic/acyclic nature of the graph.
lPruning such arcs may
produce additional leaves.
lPrune until no
further pruning is possible:
lIf the result is empty, the
original graph was acyclic.
lIf not, it was cyclic.