OAI/Combinatorics/ExpectationThreshold/ThresholdCompactness.lean

GitHub source file

2 declarations, 0 contain sorry, 0 declared as axioms

Compactness of the fractional feasible densities

The cover coefficients and the density range over closed unit intervals. The coverage inequalities and the polynomial cost bound cut out a closed subset of their compact product. Its projection is exactly the set of fractionally feasible densities, including when that set is empty.

  1. theorem OAI.TalagrandThreshold.continuous_fracCost line 26

    Source documentation

    The fractional cost is jointly continuous in the density and coefficients.

    theorem continuous_fracCost :
        Continuous (fun z : ℝ × (Finset α → ℝ) => fracCost z.1 z.2) := by
    …

    Mentions: OAI.TalagrandThreshold.fracCost

  2. theorem OAI.TalagrandThreshold.isCompact_fractionalFeasible line 34

    Source documentation

    Fractional feasibility is the projection of the actual compact set of covers.

    theorem isCompact_fractionalFeasible (F : Family α) :
        IsCompact (fractionalFeasible F) := by
    …

    Mentions: OAI.TalagrandThreshold.Family, OAI.TalagrandThreshold.fractionalFeasible