OAI/GroupTheory/PolycyclicRecognition/Algebra/GromovGrowthBridge.lean

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3 declarations, 0 contain sorry, 0 declared as axioms

Gromov's theorem from Aaron Hill's formalization

Aaron Hill's FormalConjecturesCheck.gromov_forward proves Gromov's polynomial-growth theorem for arbitrary groups. Its list-defined Cayley balls agree with the finite word balls used here, and their polynomial bounds are equivalent without an additional finite-generation or countability hypothesis.

  1. theorem OAI.PolycyclicRecognition.cayleyBall_eq_wordBall line 21

    Source documentation

    For symmetric generators the two concrete definitions of word ball agree.

    theorem cayleyBall_eq_wordBall (T : Finset J)
        (hT : ∀ t ∈ T, t⁻¹ ∈ T) (n : ℕ) :
        FormalConjecturesCheck.CayleyBall (T : Set J) n = (wordBall T n : Set J) := by
    …

    Mentions: OAI.PolycyclicRecognition.wordBall

  2. theorem OAI.PolycyclicRecognition.growthFunction_eq_card_wordBall line 36

    Source documentation

    The imported theorem's growth function counts exactly our finite ball.

    theorem growthFunction_eq_card_wordBall (T : Finset J)
        (hT : ∀ t ∈ T, t⁻¹ ∈ T) (n : ℕ) :
        FormalConjecturesCheck.GrowthFunction (T : Set J) n = (wordBall T n).card := by
    …

    Mentions: OAI.PolycyclicRecognition.wordBall

  3. theorem OAI.PolycyclicRecognition.hasPolynomialGrowth_of_wordBall line 44

    Source documentation

    The positive real constant in the imported growth convention can absorb both the shift by one and a possibly zero natural constant.

    theorem hasPolynomialGrowth_of_wordBall (T : Finset J)
        (hT : ∀ t ∈ T, t⁻¹ ∈ T)
        (hgen : Subgroup.closure (T : Set J) = ⊤)
        (hgrowth : ∃ C b : ℕ, ∀ n, (wordBall T n).card ≤ C * (1 + n) ^ b) :
        FormalConjecturesCheck.HasPolynomialGrowth J := by
    …

    Mentions: OAI.PolycyclicRecognition.wordBall