Documentation

PFR.Mathlib.Probability.Independence.Kernel

theorem ProbabilityTheory.kernel.IndepFun.ae_eq' {α : Type u_6} {Ω : Type u_5} {β : Type u_1} {β' : Type u_2} {_mα : MeasurableSpace α} {_mΩ : MeasurableSpace Ω} {κ : (ProbabilityTheory.kernel α Ω)} {μ : MeasureTheory.Measure α} {mβ : MeasurableSpace β} {mβ' : MeasurableSpace β'} {f : Ωβ} {f' : Ωβ} {g : Ωβ'} {g' : Ωβ'} (hfg : ProbabilityTheory.kernel.IndepFun f g κ μ) (hf : ∀ᵐ (a : α) ∂μ, (κ a).ae.EventuallyEq f f') (hg : ∀ᵐ (a : α) ∂μ, (κ a).ae.EventuallyEq g g') :

in mathlib as of 4d385393cd569f08ac30425ef886a57bb10daaa5 (TODO: bump)

theorem ProbabilityTheory.kernel.iIndepFun.comp {α : Type u_9} {Ω : Type u_8} {ι : Type u_7} {_mα : MeasurableSpace α} {_mΩ : MeasurableSpace Ω} {κ : (ProbabilityTheory.kernel α Ω)} {μ : MeasureTheory.Measure α} {β : ιType u_5} {γ : ιType u_6} {m : (i : ι) → MeasurableSpace (β i)} {mγ : (i : ι) → MeasurableSpace (γ i)} {f : (i : ι) → Ωβ i} (h : ProbabilityTheory.kernel.iIndepFun m f κ μ) (g : (i : ι) → β iγ i) (hg : ∀ (i : ι), Measurable (g i)) :
ProbabilityTheory.kernel.iIndepFun (fun (i : ι) => g i f i) κ μ
theorem ProbabilityTheory.kernel.iIndepFun.finsets {α : Type u_9} {Ω : Type u_8} {ι : Type u_10} {_mα : MeasurableSpace α} {_mΩ : MeasurableSpace Ω} {κ : (ProbabilityTheory.kernel α Ω)} {μ : MeasureTheory.Measure α} {β : ιType u_5} {m : (i : ι) → MeasurableSpace (β i)} {f : (i : ι) → Ωβ i} [ProbabilityTheory.IsMarkovKernel κ] {J : Type u_7} [Fintype J] (S : JFinset ι) (h_disjoint : Set.univ.PairwiseDisjoint S) (hf_Indep : ProbabilityTheory.kernel.iIndepFun m f κ μ) (hf_meas : ∀ (i : ι), Measurable (f i)) :
ProbabilityTheory.kernel.iIndepFun (fun (x : J) => MeasurableSpace.pi) (fun (j : J) (a : Ω) (i : { x : ι // x S j }) => f (i) a) κ μ

If f is a family of mutually independent random variables, (S j)ⱼ are pairwise disjoint finite index sets, then the tuples formed by f i for i ∈ S j are mutually independent, when seen as a family indexed by J.

theorem ProbabilityTheory.kernel.iIndepFun.finsets_comp {α : Type u_10} {Ω : Type u_9} {ι : Type u_11} {_mα : MeasurableSpace α} {_mΩ : MeasurableSpace Ω} {κ : (ProbabilityTheory.kernel α Ω)} {μ : MeasureTheory.Measure α} {β : ιType u_5} {m : (i : ι) → MeasurableSpace (β i)} {f : (i : ι) → Ωβ i} [ProbabilityTheory.IsMarkovKernel κ] {J : Type u_7} [Fintype J] (S : JFinset ι) (h_disjoint : Set.univ.PairwiseDisjoint S) (hf_Indep : ProbabilityTheory.kernel.iIndepFun m f κ μ) (hf_meas : ∀ (i : ι), Measurable (f i)) (γ : JType u_8) {mγ : (j : J) → MeasurableSpace (γ j)} (φ : (j : J) → ((i : { x : ι // x S j }) → β i)γ j) (hφ : ∀ (j : J), Measurable (φ j)) :
ProbabilityTheory.kernel.iIndepFun (fun (j : J) (a : Ω) => φ j fun (i : { x : ι // x S j }) => f (i) a) κ μ

If f is a family of mutually independent random variables, (S j)ⱼ are pairwise disjoint finite index sets, and φ j is a function that maps the tuple formed by f i for i ∈ S j to a measurable space γ j, then the family of random variables formed by φ j (f i)_{i ∈ S j} and indexed by J is iIndep.