OAI/Combinatorics/Ramsey/CycleClique/Construction/OptimalPathSystem.lean

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5 declarations, 0 contain sorry, 0 declared as axioms

Existence and the exact optimality criterion for manuscript Section 6.

  1. structure OAI.CycleClique.Construction.ExpandedPathSystem.IsOptimal line 13

    Source documentation

    Maximize the total amount below k+1-|Q|, then minimize the number of assigned paths. Both optimization orders are on natural numbers.

    structure IsOptimal (S : ExpandedPathSystem G Q) (k : ℕ) : Prop where
    …

    Mentions: OAI.CycleClique.Construction.ExpandedPathSystem

  2. theorem OAI.CycleClique.Construction.ExpandedPathSystem.exists_optimal line 20

    Source documentation

    The empty system ensures existence, even when the amount budget is zero.

    theorem exists_optimal (G : SimpleGraph V) (Q : Finset V) (k : ℕ) :
        ∃ S : ExpandedPathSystem G Q, S.IsOptimal k := by
    …

    Mentions: OAI.CycleClique.Construction.ExpandedPathSystem

  3. theorem OAI.CycleClique.Construction.ExpandedPathSystem.incident_le line 45
  4. theorem OAI.CycleClique.Construction.ExpandedPathSystem.IsOptimal.criterion line 51

    Source documentation

    Manuscript Lemma path:optimality, retaining its exact indicator and the secondary minimization of the number of assigned paths.

    theorem IsOptimal.criterion {S : ExpandedPathSystem G Q} {k : ℕ}
        (hopt : S.IsOptimal k) (hk : 3 ≤ k) (hQk : Q.card ≤ k)
        (hQ : G.IsClique (Q : Set V)) (hcycle : ¬ HasCycle G (k + 1))
        (T : ExpandedPathSystem G Q)
        (hlow : S.amount + (if S.assignedCount ≤ T.assignedCount then 1 else 0) ≤ T.amount)
        (hhigh : T.amount + T.incident ≤ k + 1) : False := by
    …

    Mentions: OAI.CycleClique.Construction.ExpandedPathSystem, OAI.CycleClique.Construction.HasCycle

  5. theorem OAI.CycleClique.Construction.ExpandedPathSystem.IsOptimal.no_one_vertex_increase line 70

    Source documentation

    A valid improvement by one outside vertex is impossible, regardless of how the number of represented paths changes.

    theorem IsOptimal.no_one_vertex_increase {S : ExpandedPathSystem G Q} {k : ℕ}
        (hopt : S.IsOptimal k) (hk : 3 ≤ k) (hQk : Q.card ≤ k)
        (hQ : G.IsClique (Q : Set V)) (hcycle : ¬ HasCycle G (k + 1))
        (T : ExpandedPathSystem G Q) (hinc : T.amount = S.amount + 1) : False := by
    …

    Mentions: OAI.CycleClique.Construction.ExpandedPathSystem, OAI.CycleClique.Construction.HasCycle