import Mathlib import OAI.Probability.CriticalPercolation.Classification.WeakGromovMainBoundary import OAI.Probability.CriticalPercolation.Harmonic.WeakGromovHarmonic namespace OAI section noncomputable section open Set Function Topology open scoped Classical Pointwise namespace CriticalPercolation.CompactQuotient lemma virtuallyNilpotent_of_sparse_word_growth {A : Type*} [Group A] (hg : HasSparsePolynomialWordGrowth A) : Group.IsVirtuallyNilpotent A := by obtain ⟨S,hSf,h1,hi,hgen,d,hg⟩ := hg exact SparseGrowth.sparse_polynomial_virtuallyNilpotent d A ⟨S,hSf,h1,hi,hgen,1,by simpa only [one_mul] using hg⟩ end CriticalPercolation.CompactQuotient namespace CriticalPercolation.GraphTopology lemma no_weak_Gromov_quotient_counterexample {X : Type*} (Γ : SimpleGraph X) : ¬HasWeakGromovQuotientCounterexample Γ := by let _ : TopologicalSpace X := ⊥ let _ : TopologicalSpace (Γ ≃g Γ) := autTopology Γ rintro ⟨H,hn,_,_,_,hg,hfail⟩ let _ := hn exact hfail (CompactQuotient.virtuallyNilpotent_of_sparse_word_growth hg) end CriticalPercolation.GraphTopology end end end OAI