Packing directed circuits


We prove a conjecture of Younger, that for every integern≥0 there exists an integert≥0 such that for every digraphG, eitherG hasn vertex-disjoint directed circuits, orG can be made acyclic by deleting at mostt vertices.

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Additional information

Research partially supported by DONET ECHM contract CHRXCT930090.

Research partially supported by DIMACS, by NSF grant DMS-9401981 and by ONR grant N00014-92-J-1965, and partially performed under a consulting agreement with Bellcore.

Research partially supported by DIMACS, by Université de Paris VI, by NSF grant DMS-9303761 and by ONR grant N00014-93-1-0325, and partially performed under a consulting agreement with Bellcore.

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Reed, B., Robertson, N., Seymour, P. et al. Packing directed circuits. Combinatorica 16, 535–554 (1996).

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Mathematics Subject Classification (1991)

  • 05 C 20
  • 05 C 38
  • 05 C 70