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Complexitylib.Algebraic.LowerBound.Cutwidth.Extractor.Condenser.Parameters.Sparse.Internal

Rounding and degree-budget arithmetic for sparse field sizes #

The upper logarithm rounds the field bit length to twice a power of three. Ceiling division controls the coordinate count. The rate inequality is integer-valued, so no logarithm or real rounding convention is hidden.

theorem Algebraic.Cutwidth.Extractor.Internal.sparsePowerBits_pos {u T : ℕ} (rate : 0 < u) (positive : 0 < T) :
theorem Algebraic.Cutwidth.Extractor.Internal.condenserCoordinates_output {u k r b : ℕ} (rate : u * b ≤ (u + 1) * r) :
u * (condenserCoordinates k r * b) ≤ (u + 1) * k + u * b
theorem Algebraic.Cutwidth.Extractor.Internal.condenserCoordinates_loss {D k r T : ℕ} {error : ℝ} (positive : 0 < r) (budget : ↑D * ↑k ≤ error * 2 ^ T) :
↑((D - 1) * (2 ^ r - 1) * condenserCoordinates k r) / 2 ^ (r + T) ≤ error
theorem Algebraic.Cutwidth.Extractor.Internal.sparseCondenser_loss {u T D k : ℕ} {error : ℝ} (rate : 0 < u) (positive : 0 < T) (budget : ↑D * ↑k ≤ error * 2 ^ T) :
↑((D - 1) * (2 ^ sparsePowerBits u T - 1) * condenserCoordinates k (sparsePowerBits u T)) / 2 ^ sparseFieldBits u T ≤ error