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

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2 declarations, 0 contain sorry, 0 declared as axioms

Joining disjoint paths through a clique

The expansions of the chains of a path system are disjoint simple paths with endpoints in the clique. Joining these paths, including any selected singleton clique vertices, gives the exact cycle used in path:interval.

  1. theorem OAI.CycleClique.Construction.chain_of_pairwise line 17

    Distinct definitions of this name: OAI/Combinatorics/Ramsey/CycleClique/Construction/CliqueTraversal.lean:24 (different declaration text). Qualify references as OAI.CycleClique.Construction.chain_of_pairwise@path.

  2. theorem OAI.CycleClique.Construction.hasCycle_of_disjoint_clique_paths line 26

    Source documentation

    Disjoint simple paths whose endpoints lie in a common clique can be closed into a cycle through exactly all their vertices.

    theorem hasCycle_of_disjoint_clique_paths {V : Type*} {G : SimpleGraph V}
        {Q : Set V} (hQ : G.IsClique Q) (L : List (List V))
        (hnonempty : ∀ l ∈ L, l ≠ [])
        (hpaths : ∀ l ∈ L, l.Nodup ∧ l.IsChain G.Adj)
        (hdisjoint : L.Pairwise List.Disjoint)
        (hendpoints : ∀ l ∈ L,
          (∀ v ∈ l.head?, v ∈ Q) ∧ (∀ v ∈ l.getLast?, v ∈ Q))
        (hlen : 3 ≤ L.flatten.length) : HasCycle G L.flatten.length := by
    …

    Mentions: OAI.CycleClique.Construction.HasCycle