LeanMachineLearning exposition

Learning.eq_trajMeasure_map_frestrictLe_of_isAlgEnvSeqUntil๐Ÿ”—

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eq_trajMeasure_map_frestrictLe_of_isAlgEnvSeqUntil๐Ÿ”—

LemmaLearning.eq_trajMeasure_map_frestrictLe_of_isAlgEnvSeqUntil

No docstring.

๐Ÿ”—theorem
Learning.eq_trajMeasure_map_frestrictLe_of_isAlgEnvSeqUntil.{u_1, u_2, u_4} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} {ฮฉ : Type u_4} {mฮฉ : MeasurableSpace ฮฉ} {alg : Algorithm ๐“ ๐“จ} {env : Environment ๐“ ๐“จ} {P : MeasureTheory.Measure ฮฉ} [MeasureTheory.IsProbabilityMeasure P] {Aโ‚ : โ„• โ†’ ฮฉ โ†’ ๐“} {Rโ‚ : โ„• โ†’ ฮฉ โ†’ ๐“จ} {N : โ„•} (h : IsAlgEnvSeqUntil Aโ‚ Rโ‚ alg env P N) : MeasureTheory.Measure.map (fun ฯ‰ n => (Aโ‚ (โ†‘n) ฯ‰, Rโ‚ (โ†‘n) ฯ‰)) P = MeasureTheory.Measure.map (Preorder.frestrictLe N) (trajMeasure alg env)
Learning.eq_trajMeasure_map_frestrictLe_of_isAlgEnvSeqUntil.{u_1, u_2, u_4} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} {ฮฉ : Type u_4} {mฮฉ : MeasurableSpace ฮฉ} {alg : Algorithm ๐“ ๐“จ} {env : Environment ๐“ ๐“จ} {P : MeasureTheory.Measure ฮฉ} [MeasureTheory.IsProbabilityMeasure P] {Aโ‚ : โ„• โ†’ ฮฉ โ†’ ๐“} {Rโ‚ : โ„• โ†’ ฮฉ โ†’ ๐“จ} {N : โ„•} (h : IsAlgEnvSeqUntil Aโ‚ Rโ‚ alg env P N) : MeasureTheory.Measure.map (fun ฯ‰ n => (Aโ‚ (โ†‘n) ฯ‰, Rโ‚ (โ†‘n) ฯ‰)) P = MeasureTheory.Measure.map (Preorder.frestrictLe N) (trajMeasure alg env)

Code

lemma eq_trajMeasure_map_frestrictLe_of_isAlgEnvSeqUntil
    (h : IsAlgEnvSeqUntil Aโ‚ Rโ‚ alg env P N) :
    P.map (fun ฯ‰ (n : Iic N) โ†ฆ (Aโ‚ n ฯ‰, Rโ‚ n ฯ‰)) =
      (trajMeasure alg env).map (Preorder.frestrictLe N)
Type uses (4)
Body uses (7)
Used by (1)

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Proof
by
  rw [trajMeasure]
  have h := Kernel.eq_trajMeasure_map_frestrictLe (Y := fun n ฯ‰ โ†ฆ (Aโ‚ n ฯ‰, Rโ‚ n ฯ‰))
    (P := P) (ฮผโ‚€ := alg.p0 โŠ—โ‚˜ env.ฮฝ0) (ฮบ := stepKernel alg env) ?_ (fun n hn โ†ฆ ?_) (N := N)
  ยท exact h
  ยท exact h.hasLaw_step_zero
  ยท exact h.hasCondDistrib_step n hn

Dependency graph

Type dependencies (4)

Algorithm๐Ÿ”—

StructureLearning.Algorithm

A stochastic, sequential algorithm.

๐Ÿ”—structure
Learning.Algorithm.{u_4, u_5} (๐“ : Type u_4) (๐“จ : Type u_5) [MeasurableSpace ๐“] [MeasurableSpace ๐“จ] : Type (max u_4 u_5)
Learning.Algorithm.{u_4, u_5} (๐“ : Type u_4) (๐“จ : Type u_5) [MeasurableSpace ๐“] [MeasurableSpace ๐“จ] : Type (max u_4 u_5)

Code

structure Algorithm (๐“ ๐“จ : Type*) [MeasurableSpace ๐“] [MeasurableSpace ๐“จ] where
  /-- Policy or sampling rule: distribution of the next action. -/
  policy : (n : โ„•) โ†’ Kernel (Iic n โ†’ ๐“ ร— ๐“จ) ๐“
  /-- The policy is a Markov kernel. -/
  [h_policy : โˆ€ n, IsMarkovKernel (policy n)]
  /-- Distribution of the first action. -/
  p0 : Measure ๐“
  /-- The first action distribution is a probability measure. -/
  [hp0 : IsProbabilityMeasure p0]
Used by (216)

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Environment๐Ÿ”—

StructureLearning.Environment

A stochastic environment.

๐Ÿ”—structure
Learning.Environment.{u_4, u_5} (๐“ : Type u_4) (๐“จ : Type u_5) [MeasurableSpace ๐“] [MeasurableSpace ๐“จ] : Type (max u_4 u_5)
Learning.Environment.{u_4, u_5} (๐“ : Type u_4) (๐“จ : Type u_5) [MeasurableSpace ๐“] [MeasurableSpace ๐“จ] : Type (max u_4 u_5)

Code

structure Environment (๐“ ๐“จ : Type*) [MeasurableSpace ๐“] [MeasurableSpace ๐“จ] where
  /-- Distribution of the next observation as function of the past history. -/
  feedback : (n : โ„•) โ†’ Kernel ((Iic n โ†’ ๐“ ร— ๐“จ) ร— ๐“) ๐“จ
  /-- The feedback kernels are Markov kernels. -/
  [h_feedback : โˆ€ n, IsMarkovKernel (feedback n)]
  /-- Distribution of the first observation given the first action. -/
  ฮฝ0 : Kernel ๐“ ๐“จ
  /-- The initial observation kernel is a Markov kernel. -/
  [hp0 : IsMarkovKernel ฮฝ0]
Used by (128)

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IsAlgEnvSeqUntil๐Ÿ”—

StructureLearning.IsAlgEnvSeqUntil

An algorithm-environment sequence: a sequence of actions and feedbacks generated by an algorithm interacting with an environment.

๐Ÿ”—structure
Learning.IsAlgEnvSeqUntil.{u_1, u_2, u_3} {๐“ : Type u_1} {๐“จ : Type u_2} {ฮฉ : Type u_3} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} {mฮฉ : MeasurableSpace ฮฉ} (A : โ„• โ†’ ฮฉ โ†’ ๐“) (Y : โ„• โ†’ ฮฉ โ†’ ๐“จ) (alg : Algorithm ๐“ ๐“จ) (env : Environment ๐“ ๐“จ) (P : MeasureTheory.Measure ฮฉ) [MeasureTheory.IsFiniteMeasure P] (N : โ„•) : Prop
Learning.IsAlgEnvSeqUntil.{u_1, u_2, u_3} {๐“ : Type u_1} {๐“จ : Type u_2} {ฮฉ : Type u_3} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} {mฮฉ : MeasurableSpace ฮฉ} (A : โ„• โ†’ ฮฉ โ†’ ๐“) (Y : โ„• โ†’ ฮฉ โ†’ ๐“จ) (alg : Algorithm ๐“ ๐“จ) (env : Environment ๐“ ๐“จ) (P : MeasureTheory.Measure ฮฉ) [MeasureTheory.IsFiniteMeasure P] (N : โ„•) : Prop

Code

structure IsAlgEnvSeqUntil
    (A : โ„• โ†’ ฮฉ โ†’ ๐“) (Y : โ„• โ†’ ฮฉ โ†’ ๐“จ) (alg : Algorithm ๐“ ๐“จ) (env : Environment ๐“ ๐“จ)
    (P : Measure ฮฉ) [IsFiniteMeasure P] (N : โ„•) : Prop where
  /-- The action sequence is measurable. -/
  measurable_action n : Measurable (A n) := by fun_prop
  /-- The feedback sequence is measurable. -/
  measurable_feedback n : Measurable (Y n) := by fun_prop
  /-- The first action has the correct law. -/
  hasLaw_action_zero : HasLaw (fun ฯ‰ โ†ฆ (A 0 ฯ‰)) alg.p0 P
  /-- The first feedback has the correct conditional distribution. -/
  hasCondDistrib_feedback_zero : HasCondDistrib (Y 0) (A 0) env.ฮฝ0 P
  /-- The next action has the correct conditional distribution given the history. -/
  hasCondDistrib_action n (hn : n < N) :
    HasCondDistrib (A (n + 1)) (history A Y n) (alg.policy n) P
  /-- The next feedback has the correct conditional distribution given the history and
  next action. -/
  hasCondDistrib_feedback n (hn : n < N) :
    HasCondDistrib (Y (n + 1)) (fun ฯ‰ โ†ฆ (history A Y n ฯ‰, A (n + 1) ฯ‰))
      (env.feedback n) P
Type uses (3)
Used by (22)

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trajMeasure๐Ÿ”—

DefinitionLearning.trajMeasure

Measure on the sequence of actions and observations generated by the algorithm/environment.

๐Ÿ”—def
Learning.trajMeasure.{u_1, u_2} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} (alg : Algorithm ๐“ ๐“จ) (env : Environment ๐“ ๐“จ) : MeasureTheory.Measure (โ„• โ†’ ๐“ ร— ๐“จ)
Learning.trajMeasure.{u_1, u_2} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} (alg : Algorithm ๐“ ๐“จ) (env : Environment ๐“ ๐“จ) : MeasureTheory.Measure (โ„• โ†’ ๐“ ร— ๐“จ)

Code

noncomputable
def trajMeasure (alg : Algorithm ๐“ ๐“จ) (env : Environment ๐“ ๐“จ) :
    Measure (โ„• โ†’ ๐“ ร— ๐“จ) :=
  Kernel.trajMeasure (alg.p0 โŠ—โ‚˜ env.ฮฝ0) (stepKernel alg env)
deriving IsProbabilityMeasure
Type uses (2)
Body uses (2)
Used by (19)

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All dependencies, transitively (5)

history๐Ÿ”—

DefinitionLearning.history

History of the algorithm-environment sequence up to time n.

๐Ÿ”—def
Learning.history.{u_1, u_2, u_3} {๐“ : Type u_1} {๐“จ : Type u_2} {ฮฉ : Type u_3} (A : โ„• โ†’ ฮฉ โ†’ ๐“) (Y : โ„• โ†’ ฮฉ โ†’ ๐“จ) (n : โ„•) (ฯ‰ : ฮฉ) : โ†ฅ(Finset.Iic n) โ†’ ๐“ ร— ๐“จ
Learning.history.{u_1, u_2, u_3} {๐“ : Type u_1} {๐“จ : Type u_2} {ฮฉ : Type u_3} (A : โ„• โ†’ ฮฉ โ†’ ๐“) (Y : โ„• โ†’ ฮฉ โ†’ ๐“จ) (n : โ„•) (ฯ‰ : ฮฉ) : โ†ฅ(Finset.Iic n) โ†’ ๐“ ร— ๐“จ

Code

def history (A : โ„• โ†’ ฮฉ โ†’ ๐“) (Y : โ„• โ†’ ฮฉ โ†’ ๐“จ) (n : โ„•) (ฯ‰ : ฮฉ) : Iic n โ†’ ๐“ ร— ๐“จ :=
  fun i โ†ฆ (A i ฯ‰, Y i ฯ‰)
Used by (72)

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stepKernel๐Ÿ”—

DefinitionLearning.stepKernel

Kernel describing the distribution of the next action-feedback pair given the history up to n.

๐Ÿ”—def
Learning.stepKernel.{u_1, u_2} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} (alg : Algorithm ๐“ ๐“จ) (env : Environment ๐“ ๐“จ) (n : โ„•) : ProbabilityTheory.Kernel (โ†ฅ(Finset.Iic n) โ†’ ๐“ ร— ๐“จ) (๐“ ร— ๐“จ)
Learning.stepKernel.{u_1, u_2} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} (alg : Algorithm ๐“ ๐“จ) (env : Environment ๐“ ๐“จ) (n : โ„•) : ProbabilityTheory.Kernel (โ†ฅ(Finset.Iic n) โ†’ ๐“ ร— ๐“จ) (๐“ ร— ๐“จ)

Code

noncomputable
def stepKernel (alg : Algorithm ๐“ ๐“จ) (env : Environment ๐“ ๐“จ) (n : โ„•) :
    Kernel (Iic n โ†’ ๐“ ร— ๐“จ) (๐“ ร— ๐“จ) :=
  alg.policy n โŠ—โ‚– env.feedback n
deriving IsMarkovKernel
Type uses (2)
Used by (17)

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instIsMarkovKernelForallSubtypeNatMemFinsetIicProdPolicy๐Ÿ”—

InstanceLearning.instIsMarkovKernelForallSubtypeNatMemFinsetIicProdPolicy

No docstring.

๐Ÿ”—theorem
Learning.instIsMarkovKernelForallSubtypeNatMemFinsetIicProdPolicy.{u_1, u_2} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} (alg : Algorithm ๐“ ๐“จ) (n : โ„•) : ProbabilityTheory.IsMarkovKernel (Algorithm.policy alg n)
Learning.instIsMarkovKernelForallSubtypeNatMemFinsetIicProdPolicy.{u_1, u_2} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} (alg : Algorithm ๐“ ๐“จ) (n : โ„•) : ProbabilityTheory.IsMarkovKernel (Algorithm.policy alg n)

Code

instance (alg : Algorithm ๐“ ๐“จ) (n : โ„•) : IsMarkovKernel (alg.policy n)
Type uses (1)
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Proof
alg.h_policy n

instIsMarkovKernelProdForallSubtypeNatMemFinsetIicFeedback๐Ÿ”—

InstanceLearning.instIsMarkovKernelProdForallSubtypeNatMemFinsetIicFeedback

No docstring.

๐Ÿ”—theorem
Learning.instIsMarkovKernelProdForallSubtypeNatMemFinsetIicFeedback.{u_1, u_2} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} (env : Environment ๐“ ๐“จ) (n : โ„•) : ProbabilityTheory.IsMarkovKernel (Environment.feedback env n)
Learning.instIsMarkovKernelProdForallSubtypeNatMemFinsetIicFeedback.{u_1, u_2} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} (env : Environment ๐“ ๐“จ) (n : โ„•) : ProbabilityTheory.IsMarkovKernel (Environment.feedback env n)

Code

instance (env : Environment ๐“ ๐“จ) (n : โ„•) : IsMarkovKernel (env.feedback n)
Type uses (1)
Used by (5)

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Proof
env.h_feedback n

instIsMarkovKernelForallSubtypeNatMemFinsetIicProdStepKernel๐Ÿ”—

InstanceLearning.instIsMarkovKernelForallSubtypeNatMemFinsetIicProdStepKernel

No docstring.

๐Ÿ”—theorem
Learning.instIsMarkovKernelForallSubtypeNatMemFinsetIicProdStepKernel.{u_1, u_2} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} (alg : Algorithm ๐“ ๐“จ) (env : Environment ๐“ ๐“จ) (n : โ„•) : ProbabilityTheory.IsMarkovKernel (stepKernel alg env n)
Learning.instIsMarkovKernelForallSubtypeNatMemFinsetIicProdStepKernel.{u_1, u_2} {๐“ : Type u_1} {๐“จ : Type u_2} {m๐“ : MeasurableSpace ๐“} {m๐“จ : MeasurableSpace ๐“จ} (alg : Algorithm ๐“ ๐“จ) (env : Environment ๐“ ๐“จ) (n : โ„•) : ProbabilityTheory.IsMarkovKernel (stepKernel alg env n)

Code

deriving IsMarkovKernel
Type uses (3)
Body uses (2)
Used by (10)

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Proof
deriving IsMarkovKernel