InformationTheory.Shannon.FisherInfo.DeBruijnAssembly
Per-time de Bruijn identity — assembly #
Aggregates the submodules that prove the per-time de Bruijn identity
debruijnIdentityV2_holds_assembled for a general X. This file is placed downstream of
the atom supplier FisherInfo/DeBruijnPerTime.lean (which imports FisherInfo/DeBruijn.lean)
so that the assembly can use those atoms without an import cycle.
Implementation notes #
The per-time identity is assembled from the atoms by: identifying the path density with
convDensityAdd; rewriting the entropy as ∫ negMulLog pPath; differentiating under the
integral (entropy_hasDerivAt_via_parametric); applying the heat equation
(heatFlow_density_heat_equation); integrating by parts (debruijn_ibp_step); and matching
the result to (1/2) · fisherInfoOfDensityReal h_reg.density_t (fisher_from_logDeriv).
The regularity discharges (Gaussian-tail domination, integrand measurability, global
C¹-ness, chain-rule plumbing) are factored into named private lemmas in the submodules.