Documentation

LeanPool.Superdiffusion.Algsuperdiff.Section3.Provider.Induction.StateCalculus

StateCalculus #

Ported from scottnarmstrong/Superdiffusion at 7f20476385d4af418f110303085ad0740c9eba46. Module imports, support namespace and local option directives adapted for Lean Pool.

The state calculus of the Section 3.6 induction #

Support layer for the two induction roots p.induction.step and p.induction.bounds. The roots themselves are NOT declared here: they wait on Algsuperdiff.Frozen.Section3.multiscale_estimate. This module delivers the surrounding calculus of Algsuperdiff.Frozen.Section3.inductionState:

The frozen definition's E-occurrences #

inductionState M m0 E is a conjunction of two forall m <= m0 clauses. The first (the sigmaBar sandwich) does not mention E at all. The second is a Probability.IsTwoTermBigOWith display whose two amplitudes are

So every occurrence of E in the real definition is monotone and inductionState_mono_E is unconditional. No non-monotone occurrence exists.

Sources #

1. Amplitude monotonicity of the two-term display #

2. Monotonicity of the induction state in the budget E #

The induction state is monotone in its budget.

Both E-occurrences of the frozen definition are increasing in E: the Gamma_2 amplitude E s^{-1} sqrt gamma visibly, and the Gamma_{1/2} amplitude (s^{-1})^2 exp (-(E^{-1})^3 gamma^{-1}) because 1 <= E makes (E^{-1})^3 decreasing. Enlarging both amplitudes weakens the display, so no hypothesis beyond (E : R) <= (E' : R) is needed.

3. The integer-iteration scaffold #

From a base scale and a one-scale step to every integer scale.

Above the base scale this is Int.leInduction; below it the conclusion is already contained in the base case, because both clauses of the frozen definition are forall m <= m0 (the proved ...ApproximateRecurrence.Closure.inductionState_mono).

The E-enlarging iteration. The base case holds at the smaller budget and the one-scale step at the larger budget E; the bridge is inductionState_mono_E. This is the manuscript's C c_star^{-1/2} |-> C c_star^{-1} bump.

4. The s^{-2} to s-free absorption of the rare lane #

The transcendental step is confined to pow_three_le_const_mul_exp; the arithmetic core inv_sq_le_of_regime sees exp only as an opaque positive real X.

theorem Algsuperdiff.Section3.Provider.Induction.inv_sq_mul_exp_le_exp_of_regime {gamma cst C s : ℝ} (hgamma : 0 < gamma) (hcs0 : 0 < cst) (hcs : cst ≤ 3 / 2) (hC : 6 ≤ C) (hreg : gamma ≤ C⁻¹ ^ 10 * cst ^ 10) (hs8 : 8 * gamma ≤ s) :
s⁻¹ ^ 2 * Real.exp (-((C ^ 3)⁻¹ * cst ^ 3 * gamma⁻¹)) ≤ Real.exp (-((2 * C ^ 3)⁻¹ * cst ^ 3 * gamma⁻¹))

The s^{-2} of the induction state's Gamma_{1/2} clause is absorbable at the terminal display, uniformly over the printed window s >= 8 gamma, at the cost of one enlargement C |-> 2 C^3 of the exponent constant.

The consumer-facing s-free display.

At the terminal budget E = C c_star^{-1} the induction state's Gamma_2 amplitude is already the printed C c_star^{-1} s^{-1} sqrt gamma and its Gamma_{1/2} amplitude is (s^{-1})^2 exp (-C^{-3} c_star^3 gamma^{-1}). Re-wrapping both at the single enlarged constant Cp = 2 C^3 produces exactly the first conclusion of Algsuperdiff.Frozen.Section3.induction_bounds (with C there instantiated at Cp): amplitude Cp c_star^{-1} s^{-1} sqrt gamma and the s-free exp (-(Cp^{-1} c_star^3 gamma^{-1})).

No multiscale input is used: the whole content is the E-instantiation, the absorption above, and amplitude monotonicity.

5. The epsilon-fixing of the multiscale conclusion #

The frozen multiscale_estimate conclusion carries Cms * E * s^{-1} * sqrt (epsilon * gamma) and Cms * epsilon * (s^{-1})^2 * exp (...). Fixing epsilon := (2 Cms)^{-2} makes Cms * sqrt epsilon = 1/2 and Cms * epsilon = (4 Cms)^{-1} <= 1, so both amplitudes drop to the inductionState shape at the same E.

The enlargement is admissible because every Cms-occurrence in the frozen conclusion is weakened by a larger constant, except the guard s <= Cms * epsilon of the Y-refinement clause -- and at the fixed epsilon = ((2 Cms)^2)^{-1} that guard's threshold (4 Cms)^{-1} tightens with Cms.

theorem Algsuperdiff.Section3.Provider.Induction.epsilonFix_mem_Ioc {Cms : ℝ} (hCms : 1 ≤ Cms) :
((2 * Cms) ^ 2)⁻¹ ∈ Set.Ioc 0 (1 / 2)

The fixed epsilon = (2 Cms)^{-2} lies in the admissible window Ioc 0 (1/2) of multiscale_estimate, for every Cms >= 1.

theorem Algsuperdiff.Section3.Provider.Induction.mul_sqrt_epsilonFix {Cms : ℝ} (hCms : 0 < Cms) :
Cms * √((2 * Cms) ^ 2)⁻¹ = 2⁻¹

The epsilon-fixing makes the multiscale Gamma_2 loss coefficient exactly 1/2.

theorem Algsuperdiff.Section3.Provider.Induction.multiscaleAmplitude_le_of_epsilonFix {Cms E s gamma : ℝ} (hCms : 0 < Cms) (hE : 0 ≤ E) (hs : 0 ≤ s⁻¹) :
Cms * E * s⁻¹ * √(((2 * Cms) ^ 2)⁻¹ * gamma) ≤ E * s⁻¹ * √gamma

The fixed multiscale Gamma_2 amplitude is at most the induction state's, at the same budget E.

theorem Algsuperdiff.Section3.Provider.Induction.multiscaleRareAmplitude_le_of_epsilonFix {Cms u v : ℝ} (hCms : 1 ≤ Cms) (hu : 0 ≤ u) (hv : 0 ≤ v) :
Cms * ((2 * Cms) ^ 2)⁻¹ * u * v ≤ u * v

The fixed multiscale Gamma_{1/2} amplitude is at most the induction state's: Cms * (2 Cms)^{-2} = (4 Cms)^{-1} <= 1.

6. The base bridge Cstart c_star^{-1/2} <= C c_star^{-1} #

theorem Algsuperdiff.Section3.Provider.Induction.startBudget_le_of_sqrt {cst Cstart C : ℝ} (hcs0 : 0 < cst) (hcs : cst ≤ 3 / 2) (hCstart : 0 ≤ Cstart) (hC : Cstart * √(3 / 2) ≤ C) :
Cstart * (√cst)⁻¹ ≤ C * cst⁻¹

The base bridge. Under the proved c_star <= 3/2 the base case's budget Cstart c_star^{-1/2} is below the induction budget C c_star^{-1} as soon as C >= Cstart sqrt (3/2). The equivalence is Cstart c_star^{-1/2} <= C c_star^{-1} iff Cstart sqrt c_star <= C.

theorem Algsuperdiff.Section3.Provider.Induction.one_le_terminalBudget {K cst : ℝ} (hK : 6 ≤ K) (hcs0 : 0 < cst) (hcs : cst ≤ 3 / 2) :
1 ≤ K * cst⁻¹

The terminal budget is at least one in the induction parameter regime.