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PositiveDomain
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IndisputableMonolith.Algebra.CostAlgebra on GitHub at line 517.
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All declarations in this module, on Recognition.
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514/-! ## §5b. Recognition Cost Systems and Window Aggregation -/
515
516/-- The ambient domain of recognition cost systems: positive reals. -/
517def PositiveDomain : Set ℝ := Set.Ioi 0
518
519/-- A recognition cost system packages a ratio cost, a conservation
520 functional, and a finite window length. -/
521structure RecognitionCostSystem (n : ℕ) where
522 cost : ℝ → ℝ
523 rcl : SatisfiesRCL cost
524 sigma : (Fin n → ℝ) → ℝ
525 W : ℕ
526 W_pos : 0 < W
527
528/-- The canonical conservation functional from Definition 2.7:
529 sum of logarithms on positive coordinates. -/
530noncomputable def canonicalSigma {n : ℕ} (x : Fin n → ℝ) : ℝ :=
531 ∑ i, Real.log (x i)
532
533/-- The canonical recognition cost system `(ℝ₊, J, σ, W)`. -/
534noncomputable def canonicalRecognitionCostSystem (n W : ℕ) (hW : 0 < W) :
535 RecognitionCostSystem n where
536 cost := J
537 rcl := RCL_holds
538 sigma := canonicalSigma
539 W := W
540 W_pos := hW
541
542/-- The canonical recognition cost system uses the positive reals as state space. -/
543theorem canonicalRecognitionCostSystem_domain :
544 PositiveDomain = Set.Ioi 0 := rfl
545
546/-- The canonical recognition cost system inherits balance. -/
547theorem canonicalRecognitionCostSystem_cost_one {n W : ℕ} (hW : 0 < W) :