FormalConjectures/WrittenOnTheWallII/GraphConjecture3.lean

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Explanation legend Lean4 Domain Explanation Language (L4DEL)

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L4DEL
Lean4 Domain Explanation Language

Credit: The upstream authors and contributors retain credit for the project and mathematics. lean4-explainer only renders their pinned source and adds the separately disclosed explanation layer.

Project sources: Pinned project documentation, Formal Conjectures paper, arXiv v1

3 declarations, 1 contain sorry, 0 declared as axioms

Written on the Wall II - Conjecture 3

Reference: E. DeLaVina, Written on the Wall II, Conjectures of Graffiti.pc

Imports (1)
  1. theorem WrittenOnTheWallII.GraphConjecture3.conjecture3 Documented declaration: conjecture3 sorry line 46 source

    Source documentation

    WOWII Conjecture 3

    For a connected simple graph G, the number of leaves in a maximum spanning tree satisfies Ls(G) ≥ G.indepDominationNumber * MaxTemp(G), where G.indepDominationNumber is the independent domination number and MaxTemp(G) is max_v deg(v)/(n(G) - deg(v)).

    L4DEL explanation

    WOWII Conjecture 3 For a connected simple graph G, the number of leaves in a maximum spanning tree satisfies Ls(G) ≥ G.indepDominationNumber * MaxTemp(G), where G.indepDominationNumber is the independent domination number and MaxTemp(G) is max_v deg(v)/(n(G) - deg(v)).

    Sources and attribution: Pinned Lean source (1646ca16afd6)

    depends on sorry what this means

    Statement uses: Fintype, DecidableEq, SimpleGraph, DecidableRel, SimpleGraph.Adj, Nontrivial, SimpleGraph.Connected, LE.le, Real, HMul.hMul, SimpleGraph.indepDominationNumber, SimpleGraph.MaxTemp, SimpleGraph.Ls

    Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous, OfNat.ofNat, Nat

    13 instances, coercions and auxiliary constants left out.

    Tactic trace: 7 steps

    Open to load the checked before-and-after goal states.

    theorem conjecture3 {G : SimpleGraph α} [DecidableRel G.Adj] [Nontrivial α] (h_conn : G.Connected) :
        G.indepDominationNumber * MaxTemp G ≤ Ls G := by
    …
  2. example WrittenOnTheWallII.GraphConjecture3.(example at line 54) line 54 source

    Source documentation

    The number of vertices of the two-vertex graph K₂ is 2.

    example : Fintype.card (Fin 2) = 2 := rfl
    …
  3. example WrittenOnTheWallII.GraphConjecture3.(example at line 58) line 58 source

    Source documentation

    In K₂, the temperature of vertex 0 is deg(0) / (n - deg(0)) = 1 / 1 = 1.

    example : temp_v (⊤ : SimpleGraph (Fin 2)) ⟨0, by omega⟩ = 1 := by
    …