Learning.IT.hasCondDistrib_feedback🔗

Learning.IT.hasCondDistrib_feedback.{u_1, u_2} {𝓐 : Type u_1}
  {𝓨 : Type u_2} {m𝓐 : MeasurableSpace 𝓐} {m𝓨 : MeasurableSpace 𝓨}
  (alg : Algorithm 𝓐 𝓨) (env : Environment 𝓐 𝓨) (n : ℕ) :
  ProbabilityTheory.HasCondDistrib (feedback (n + 1))
    (fun ω => (hist n ω, action (n + 1) ω)) (Environment.feedback env n)
    (trajMeasure alg env)
Learning.IT.hasCondDistrib_feedback.{u_1,
    u_2}
  {𝓐 : Type u_1} {𝓨 : Type u_2}
  {m𝓐 : MeasurableSpace 𝓐}
  {m𝓨 : MeasurableSpace 𝓨}
  (alg : Algorithm 𝓐 𝓨)
  (env : Environment 𝓐 𝓨) (n : ℕ) :
  ProbabilityTheory.HasCondDistrib
    (feedback (n + 1))
    (fun ω =>
      (hist n ω, action (n + 1) ω))
    (Environment.feedback env n)
    (trajMeasure alg env)

lemma hasCondDistrib_feedback (alg : Algorithm 𝓐 𝓨) (env : Environment 𝓐 𝓨) (n : ℕ) :
    HasCondDistrib (feedback (n + 1)) (fun ω ↦ (hist n ω, action (n + 1) ω)) (env.feedback n)
      (trajMeasure alg env)

by
  have h_step := hasCondDistrib_step alg env n
  have h_action := hasCondDistrib_action alg env n
  refine ⟨by fun_prop, ?_⟩
  rw [h_action.map_eq, ← Measure.compProd_assoc, ← stepKernel, ← h_step.map_eq,
    Measure.map_map (by fun_prop) (by fun_prop)]
  rfl

Meaning last changed in v4.34.0-rc2-1-g439785b (2026-08-23), the 4th recorded change.

Self-contained, with its dependencies inlined and proofs replaced by sorry: download the raw file · open it in the Lean web editor.

Dependency graph

Audit surface: 7 project declarations, 32 external constants

✓ Proved: no sorry anywhere in its closure

This is the tool's own reading of one build's recorded axioms, and it is not robust against an author who wants it to pass. Checking meant to be relied on should go through Comparator, which replays the proof through the kernel from an export against an explicit list of permitted axioms.