OAI/Combinatorics/GraphThreshold/GraphExpectedCopies.lean

GitHub source file

9 declarations, 0 contain sorry, 0 declared as axioms

  1. def OAI.LeanBlast.SecondKahnKalai.subgraphToComplete line 18

    Source documentation

    Regard an actual subgraph as a subgraph of the complete graph. Its vertex set, including all isolated vertices, is unchanged.

    def subgraphToComplete {G : SimpleGraph (Fin n)} (K : G.Subgraph) :
        (⊤ : SimpleGraph (Fin n)).Subgraph where
    …
  2. def OAI.LeanBlast.SecondKahnKalai.subgraphFromComplete line 27

    Source documentation

    A complete-graph subgraph whose edges occur in G is the same actual subgraph of G.

    def subgraphFromComplete (G : SimpleGraph (Fin n))
        (K : (⊤ : SimpleGraph (Fin n)).Subgraph) (hK : K.spanningCoe ≤ G) :
        G.Subgraph where
    …
  3. def OAI.LeanBlast.SecondKahnKalai.completeCopyEquiv line 37

    Source documentation

    Copies are put in bijection without choosing or counting graph embeddings.

    def completeCopyEquiv (G : SimpleGraph (Fin n)) (F : SimpleGraph V) :
        {K : G.Subgraph // Nonempty (F ≃g K.coe)} ≃
          {K : (⊤ : SimpleGraph (Fin n)).Subgraph //
            Nonempty (F ≃g K.coe) ∧ K.spanningCoe ≤ G} where
    …
  4. theorem OAI.LeanBlast.SecondKahnKalai.copyCount_eq_complete_card line 46
  5. theorem OAI.LeanBlast.SecondKahnKalai.copyCount_eq_sum_complete line 62
  6. theorem OAI.LeanBlast.SecondKahnKalai.edgeCount_spanningCoe line 76

    Source documentation

    Adding ambient isolated vertices does not change the edge count.

    theorem edgeCount_spanningCoe {G : SimpleGraph (Fin n)} (K : G.Subgraph) :
        edgeCount K.spanningCoe = edgeCount K.coe := by
    …

    Mentions: OAI.LeanBlast.SecondKahnKalai.edgeCount

  7. theorem OAI.LeanBlast.SecondKahnKalai.card_graphEdges_of_copy line 84
  8. theorem OAI.LeanBlast.SecondKahnKalai.subgraph_survival_probability line 91
  9. theorem OAI.LeanBlast.SecondKahnKalai.expectedCopies_formula line 108

    Source documentation

    The exact expected number of unlabelled, non-induced copies. The counted objects include their vertex sets, so the identity retains isolated vertices.

    theorem expectedCopies_formula (n : ℕ) (p : ℝ) (F : SimpleGraph V) :
        expectedCopies n p F =
          ((⊤ : SimpleGraph (Fin n)).copyCount F : ℝ) * p ^ edgeCount F := by
    …

    Mentions: OAI.LeanBlast.SecondKahnKalai.expectedCopies, OAI.LeanBlast.SecondKahnKalai.edgeCount