Bandits.ArrayModel.hasLaw_action_zero🔗

Bandits.ArrayModel.hasLaw_action_zero.{u_1, u_2} {𝓐 : Type u_1}
  {R : Type u_2} {m𝓐 : MeasurableSpace 𝓐} {mR : MeasurableSpace R}
  [Nonempty 𝓐] [StandardBorelSpace 𝓐] [DecidableEq 𝓐] [Countable 𝓐]
  (alg : Learning.Algorithm 𝓐 R) (ν : ProbabilityTheory.Kernel 𝓐 R)
  [ProbabilityTheory.IsMarkovKernel ν] :
  ProbabilityTheory.HasLaw (action alg 0) (Learning.Algorithm.p0 alg)
    (arrayMeasure ν)
Bandits.ArrayModel.hasLaw_action_zero.{u_1,
    u_2}
  {𝓐 : Type u_1} {R : Type u_2}
  {m𝓐 : MeasurableSpace 𝓐}
  {mR : MeasurableSpace R} [Nonempty 𝓐]
  [StandardBorelSpace 𝓐] [DecidableEq 𝓐]
  [Countable 𝓐]
  (alg : Learning.Algorithm 𝓐 R)
  (ν : ProbabilityTheory.Kernel 𝓐 R)
  [ProbabilityTheory.IsMarkovKernel ν] :
  ProbabilityTheory.HasLaw (action alg 0)
    (Learning.Algorithm.p0 alg)
    (arrayMeasure ν)

lemma hasLaw_action_zero (alg : Algorithm 𝓐 R) (ν : Kernel 𝓐 R) [IsMarkovKernel ν] :
    HasLaw (action alg 0) alg.p0 (arrayMeasure ν) where
  map_eq

by
    calc (arrayMeasure ν).map (fun ω ↦ initAlgFunction alg (ω.1 0))
    _ = ((arrayMeasure ν).fst.map (Function.eval 0)).map (initAlgFunction alg) := by
      rw [Measure.fst, Measure.map_map (by fun_prop) (by fun_prop),
        Measure.map_map (by fun_prop) (by fun_prop)]
      rfl
    _ = (volume : Measure I).map (initAlgFunction alg) := by
      simp only [arrayMeasure, Measure.fst_prod]
      rw [(measurePreserving_eval_infinitePi (fun _ ↦ volume) 0).map_eq]
    _ = alg.p0 := initAlgFunction_map alg

Meaning last changed in v4.34.0-rc2-1-g439785b (2026-08-23), the 5th 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: 12 project declarations, 91 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.