def
definition
markovOfMatrix
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IndisputableMonolith.YM.Dobrushin on GitHub at line 55.
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52variable {ι : Type} [Fintype ι]
53
54/-- Turn a strictly positive row‑stochastic real matrix into a MarkovKernel. -/
55noncomputable def markovOfMatrix (A : Matrix ι ι ℝ)
56 (hrow : ∀ i, ∑ j, A i j = 1) (hnn : ∀ i j, 0 ≤ A i j) : Dobrushin.MarkovKernel ι :=
57{ P := fun i j => A i j
58, nonneg := hnn
59, rowSum_one := hrow }
60
61/-- If all row‑row overlaps are uniformly ≥ β ∈ (0,1], we obtain a TV contraction with α = 1−β. -/
62theorem tv_contract_of_uniform_overlap {β : ℝ}
63 (hβpos : 0 < β) (hβle : β ≤ 1) :
64 Dobrushin.TVContractionMarkov (α := 1 - β) := by
65 -- special case of tv_contraction_from_overlap_lb applied to `markovOfMatrix A`
66 exact Dobrushin.tv_contraction_from_overlap_lb hβpos hβle
67
68end YM
69end IndisputableMonolith