OAI/Combinatorics/ContingencyTables/Transport/EdmondsKarpAugmentation.lean

GitHub source file

7 declarations, 0 contain sorry, 0 declared as axioms

Label monotonicity and critical arcs of a shortest augmentation

  1. lemma OAI.ContingencyTables.EdmondsKarpAugmentation.reverse_count_zero line 13
  2. lemma OAI.ContingencyTables.EdmondsKarpAugmentation.update_decrease line 22
  3. lemma OAI.ContingencyTables.EdmondsKarpAugmentation.update_new_edge line 32
  4. lemma OAI.ContingencyTables.EdmondsKarpAugmentation.update_saturates line 40
  5. theorem OAI.ContingencyTables.EdmondsKarpAugmentation.labels_monotone line 49

    Source documentation

    All old distance labels remain valid lower potentials for the new residual graph, including arcs created by cancellation of flow.

    theorem labels_monotone {c : Capacity n} {s t : Fin n} {f g : Flow n}
        (h : ShortestAugmentation c s t f g) (v : Fin n) : label c f s v ≤ label c g s v := by
    …
  6. theorem OAI.ContingencyTables.EdmondsKarpAugmentation.decrease_labels line 69

    Source documentation

    A decrease of flow on (u,v) means the augmentation used (v,u). Consequently u was one distance layer beyond v.

    theorem decrease_labels {c : Capacity n} {s t : Fin n} {f g : Flow n}
        (h : ShortestAugmentation c s t f g) (u v : Fin n) (hdec : g u v < f u v) :
        label c f s u=label c f s v+1 := by
    …
  7. theorem OAI.ContingencyTables.EdmondsKarpAugmentation.critical_arc line 85

    Source documentation

    Each augmentation has an arc which was residual, becomes saturated, and points from one finite distance layer to the next.

    theorem critical_arc {c : Capacity n} {s t : Fin n} {f g : Flow n}
        (h : ShortestAugmentation c s t f g) :
        ∃ u v : Fin n,f u v < (c u v:ℤ) ∧ g u v=(c u v:ℤ) ∧
          label c f s v=label c f s u+1 ∧ label c f s u < n := by
    …