On this page
Laws given by a density
Imports 3 library modules and 20 external
- GaussianAnalysis.probability.lindeberg
- GaussianAnalysis.probability.tuple_rows
- GaussianAnalysis.probability.conditioning
External: HB.structures, mathcomp.classical.all_ssreflect_compat, mathcomp.algebra.algebraic_hierarchy.ssralg, mathcomp.algebra.numeric_hierarchy.ssrnum, mathcomp.classical.boolp, mathcomp.classical.classical_sets, mathcomp.classical.functions, mathcomp.classical.cardinality, mathcomp.reals.reals, mathcomp.analysis.ereal, mathcomp.analysis.topology_theory.topology, mathcomp.analysis.normedtype_theory.normedtype, mathcomp.analysis.sequences, mathcomp.analysis.measure_theory.measure, mathcomp.analysis.lebesgue_measure, mathcomp.analysis.measurable_realfun, mathcomp.analysis.numfun, mathcomp.analysis.lebesgue_integral_theory.lebesgue_integral, mathcomp.analysis.charge, mathcomp.analysis.probability_theory.probability
For a probability mu on a measurable type T and a measurable f : T -> R, nonnegative everywhere, of integral one against mu, density_prob mu f is the probability A |-> int_A f dmu. Its measure is the integral of a nonnegative function, sigma-additive by semi_sigma_additive_nng_induced of MathComp-Analysis. When f is not such a density, density_prob mu f is mu itself (density_prob_default), so that density_prob mu f is a probability for every f; the results below assume prob_density mu f. density_law mu f hf is the same probability, built from a proof hf of prob_density mu f: its value on A is int_A f dmu by definition, with no fallback.
- density_probE: density_prob mu f A = int_A f dmu.
- density_prob_dominates: density_prob mu f is absolutely continuous with respect to mu.
- ge0_integral_density_prob, integrable_density_prob, integral_density_prob: integrating g against density_prob mu f is integrating g f against mu, for g nonnegative or integrable.
- density_prob_ae, eq_density_prob: a density may be changed on a mu-null set: int_A f' dmu = density_prob mu f A for measurable A when f' = f mu-almost everywhere, even if f' is negative somewhere, and two densities equal mu-almost everywhere give the same probability.
- prob_density_tuple_prod, tuple_prod_density: if f_k is a density against nu_k for every k < n, the product of the laws density_prob nu_k f_k, k < n, has the density x |-> prod_k f_k (x_k) against tuple_prod nu n. indic_tuple_box: the indicator of a box is the product of the indicators of its sides.
- density_lawE: density_law mu f hf A = int_A f dmu. density_law_prob: density_law mu f hf is density_prob mu f. integral_density_law_prob: integrals against the two agree, so every result on density_prob holds for density_law. density_law_dominates, ge0_integral_density_law, integrable_density_law, integral_density_law, eq_density_law and tuple_prod_density_law restate the results above for density_law.
prob_ | f is measurable, nonnegative everywhere, and of integral one against mu |
density_ | the probability with density f against mu, if prob_density mu f, and mu otherwise |
density_ | the probability with density f against mu, for a proof hf of prob_density mu f |
Main results
| Results | Statement |
|---|---|
For a probability mu and a measurable f >= 0 with int f dmu = 1 (prob_density mu f), density_prob mu f is the probability A |-> int_A f dmu, absolutely continuous with respect to mu; it is mu itself when f is not such a density. | |
Integrating g against density_prob mu f is integrating g f against mu, for g nonnegative or integrable. A density may be changed on a mu-null set, even to negative values: int_A f' dmu = density_prob mu f A when f' = f mu-almost everywhere. | |
If f_k is a density against nu_k for every k < n, the product of the laws density_prob nu_k f_k has the density x |-> prod_k f_k (x_k) against tuple_prod nu n. | |
The constructor with a proof that f is a density: for hf : prob_density mu f, density_law mu f hf is the probability A |-> int_A f dmu, by definition and with no fallback to mu. It is density_prob mu f, and integrals against the two agree; density_law_dominates, ge0_integral_density_law, integrable_density_law, integral_density_law, eq_density_law and tuple_prod_density_law restate the three rows above for it. |
Declarations27 exported, 13 local
forall [d : measure_display] [T : measurableType d] [R : realType], probability T R -> (T -> R) -> Prop
Definition prob_density d (T : measurableType d) (R : realType) (mu : probability T R) (f : T -> R) : Prop := [/\ measurable_fun [set: T] f, forall x, 0 <= f x & (\int[mu]_x (f x)%:E = 1)%E].
For a probability mu and a measurable f >= 0 with int f dmu = 1 (prob_density mu f), density_prob mu f is the probability A |-> int_A f dmu, absolutely continuous with respect to mu; it is mu itself when f is not such a density.
Used by 8 declarations in 1 file
forall [d : measure_display] [T : measurableType d] [R : realType], probability T R -> (T -> R) -> set T -> \bar R
Definition density_prob d (T : measurableType d) (R : realType) (mu : probability T R) (f : T -> R) : set T -> \bar R := if pselect (prob_density mu f) then fun A => (\int[mu]_(x in A) (f x)%:E)%E else mu.
Stated in the README together with prob_density.
Used by 20 declarations in 1 file
- this file: P0, P_ge0, P_sigma_additive, instance at line 105, P_setT, instance at line 113, density_prob_default, density_probE, density_prob_dominates, RN_density, ge0_integral_density_prob, integrable_density_prob, integral_density_prob, density_prob_ae, eq_density_prob, density_law_prob, integral_density_law_prob, integrable_density_law, tuple_prod_density, tuple_prod_density_law
HB declares canonical projections that the structures of the measure already provide; the warning says so. The setting lasts until the end of this file and is not exported.
Set Warnings "-redundant-canonical-projection".
Context d (T : measurableType d) (R : realType). Variables (mu : probability T R) (f : T -> R). Local Notation P := (density_prob mu f).
Let P0 : P set0 = 0%E.
Used by 1 declaration in 1 file
- this file: instance at line 105
Let P_ge0 A : (0 <= P A)%E.
Used by 1 declaration in 1 file
- this file: instance at line 105
Let P_sigma_additive : semi_sigma_additive P.
Used by 1 declaration in 1 file
- this file: instance at line 105
HB.instance Definition _ := isMeasure.Build _ _ _ P P0 P_ge0 P_sigma_additive.
Let P_setT : P [set: T] = 1%E.
Used by 1 declaration in 1 file
- this file: instance at line 113
HB.instance Definition _ := @Measure_isProbability.Build _ _ R P P_setT.
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R], ~ prob_density mu f -> density_prob mu f = mu
Stated in the README together with prob_density.
Statement as written in the source
Lemma density_prob_default : ~ prob_density mu f -> P = mu.
Context d (T : measurableType d) (R : realType). Variables (mu : probability T R) (f : T -> R). Hypothesis hf : prob_density mu f. Local Notation P := (density_prob mu f). Local Open Scope ereal_scope.
Let mF : measurable_fun [set: T] (fun x => (f x)%:E).
Used by 3 declarations in 1 file
- this file: density_prob_dominates, RN_density, integrable_density_prob
Let F0 x : 0 <= (f x)%:E.
Used by 3 declarations in 1 file
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R], prob_density mu f -> forall A : set T, density_prob mu f A = (\int[mu]_(x in A) (f x)%:E)%E
Stated in the README together with prob_density.
Statement as written in the source
Lemma density_probE A : P A = \int[mu]_(x in A) (f x)%:E.
Used by 7 declarations in 1 file
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R], prob_density mu f -> density_prob mu f `<< mu
Stated in the README together with prob_density.
Statement as written in the source
Lemma density_prob_dominates : P `<< mu.
Used by 3 declarations in 1 file
- this file: RN_density, ge0_integral_density_prob, density_law_dominates
Let RN_density : ae_eq mu [set: T] (Radon_Nikodym_SigmaFinite.f P mu) (fun x => (f x)%:E).
Used by 1 declaration in 1 file
- this file: ge0_integral_density_prob
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R], prob_density mu f -> forall [g : T -> \bar R] [E : set T], d.-measurable E -> (forall x : T, (0%R <= g x)%E) -> measurable_fun E g -> (\int[density_prob mu f]_(x in E) g x)%E = (\int[mu]_(x in E) (g x * (f x)%:E))%E
Integrating g against density_prob mu f is integrating g f against mu, for g nonnegative or integrable. A density may be changed on a mu-null set, even to negative values: int_A f' dmu = density_prob mu f A when f' = f mu-almost everywhere.
Statement as written in the source
Lemma ge0_integral_density_prob (g : T -> \bar R) E : measurable E -> (forall x, 0 <= g x) -> measurable_fun E g -> \int[P]_(x in E) g x = \int[mu]_(x in E) (g x * (f x)%:E).
Used by 3 declarations in 1 file
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R], prob_density mu f -> forall [g : T -> \bar R] [E : set T], d.-measurable E -> measurable_fun E g -> (density_prob mu f).-integrable E g <-> mu.-integrable E (fun x : T => (g x * (f x)%:E)%E)
Stated in the README together with ge0_integral_density_prob.
Statement as written in the source
Lemma integrable_density_prob (g : T -> \bar R) E : measurable E -> measurable_fun E g -> P.-integrable E g <-> mu.-integrable E (fun x => g x * (f x)%:E).
Used by 2 declarations in 1 file
- this file: integrable_density_law, integral_density_law
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R], prob_density mu f -> forall [g : T -> \bar R] [E : set T], d.-measurable E -> (density_prob mu f).-integrable E g -> (\int[density_prob mu f]_(x in E) g x)%E = (\int[mu]_(x in E) (g x * (f x)%:E))%E
Stated in the README together with ge0_integral_density_prob.
Statement as written in the source
Lemma integral_density_prob (g : T -> \bar R) E : measurable E -> P.-integrable E g -> \int[P]_(x in E) g x = \int[mu]_(x in E) (g x * (f x)%:E).
Used by 1 declaration in 1 file
- this file: integral_density_law
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R], prob_density mu f -> forall [f' : T -> R] [A : set T], d.-measurable A -> measurable_fun [set: T] f' -> ae_eq mu [set: T] (fun x : T => (f x)%:E) (fun x : T => (f' x)%:E) -> density_prob mu f A = (\int[mu]_(x in A) (f' x)%:E)%E
The density may be changed on a mu-null set, even to negative values.
Stated in the README together with ge0_integral_density_prob.
Statement as written in the source
Lemma density_prob_ae (f' : T -> R) A : measurable A -> measurable_fun [set: T] f' -> ae_eq mu [set: T] (fun x => (f x)%:E) (fun x => (f' x)%:E) -> P A = \int[mu]_(x in A) (f' x)%:E.
Used by 1 declaration in 1 file
- this file: eq_density_prob
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f f' : T -> R], prob_density mu f -> prob_density mu f' -> ae_eq mu [set: T] (fun x : T => (f x)%:E) (fun x : T => (f' x)%:E) -> forall [A : set T], d.-measurable A -> density_prob mu f A = density_prob mu f' A
Stated in the README together with ge0_integral_density_prob.
Statement as written in the source
Lemma eq_density_prob d (T : measurableType d) (R : realType) (mu : probability T R) (f f' : T -> R) : prob_density mu f -> prob_density mu f' -> ae_eq mu [set: T] (fun x => (f x)%:E) (fun x => (f' x)%:E) -> forall A, measurable A -> density_prob mu f A = density_prob mu f' A.
Used by 1 declaration in 1 file
- this file: eq_density_law
forall {d : measure_display} {T : measurableType d} {R : realType} (mu : probability T R) (f : T -> R), prob_density mu f -> set T -> \bar R
Definition density_law d (T : measurableType d) (R : realType) (mu : probability T R) (f : T -> R) (hf : prob_density mu f) : set T -> \bar R := fun A => (\int[mu]_(x in A) (f x)%:E)%E.
The constructor with the proof that f is a density: the set function A |-> int_A f dmu itself, with no fallback.
The constructor with a proof that f is a density: for hf : prob_density mu f, density_law mu f hf is the probability A |-> int_A f dmu, by definition and with no fallback to mu. It is density_prob mu f, and integrals against the two agree; density_law_dominates, ge0_integral_density_law, integrable_density_law, integral_density_law, eq_density_law and tuple_prod_density_law restate the three rows above for it.
Used by 15 declarations in 1 file
Arguments density_law {d T R} mu f hf.
Context d (T : measurableType d) (R : realType). Variables (mu : probability T R) (f : T -> R) (hf : prob_density mu f). Local Notation L := (density_law mu f hf). Local Open Scope ereal_scope.
Let mF : measurable_fun [set: T] (fun x => (f x)%:E).
Used by 1 declaration in 1 file
- this file: L_sigma_additive
Let F0 x : 0 <= (f x)%:E.
Used by 2 declarations in 1 file
- this file: L_ge0, L_sigma_additive
Let L0 : L set0 = 0.
Used by 1 declaration in 1 file
- this file: instance at line 256
Let L_ge0 A : 0 <= L A.
Used by 1 declaration in 1 file
- this file: instance at line 256
Let L_sigma_additive : semi_sigma_additive L.
Used by 1 declaration in 1 file
- this file: instance at line 256
HB.instance Definition _ := isMeasure.Build _ _ _ L L0 L_ge0 L_sigma_additive.
Let L_setT : L [set: T] = 1.
Used by 1 declaration in 1 file
- this file: instance at line 261
HB.instance Definition _ := @Measure_isProbability.Build _ _ R L L_setT.
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R] (hf : prob_density mu f) (A : set T), density_law mu f hf A = (\int[mu]_(x in A) (f x)%:E)%E
Stated in the README together with density_law.
Statement as written in the source
Lemma density_lawE A : L A = \int[mu]_(x in A) (f x)%:E.
Context d (T : measurableType d) (R : realType). Variables (mu : probability T R) (f : T -> R) (hf : prob_density mu f). Local Notation L := (density_law mu f hf). Local Open Scope ereal_scope.
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R] (hf : prob_density mu f), density_law mu f hf = density_prob mu f
density_law and density_prob agree when f is a density.
Stated in the README together with density_law.
Statement as written in the source
Lemma density_law_prob : L = density_prob mu f.
Used by 3 declarations in 1 file
- this file: density_law_dominates, eq_density_law, tuple_prod_density_law
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R] (hf : prob_density mu f) (g : T -> \bar R) (D : set T), (\int[density_law mu f hf]_(x in D) g x)%E = (\int[density_prob mu f]_(x in D) g x)%E
Stated in the README together with density_law.
Statement as written in the source
Lemma integral_density_law_prob (g : T -> \bar R) D : \int[L]_(x in D) g x = \int[density_prob mu f]_(x in D) g x.
Used by 3 declarations in 1 file
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R] (hf : prob_density mu f), density_law mu f hf `<< mu
Statement as written in the source
Lemma density_law_dominates : L `<< mu.
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R] (hf : prob_density mu f) [g : T -> \bar R] [E : set T], d.-measurable E -> (forall x : T, (0%R <= g x)%E) -> measurable_fun E g -> (\int[density_law mu f hf]_(x in E) g x)%E = (\int[mu]_(x in E) (g x * (f x)%:E))%E
Statement as written in the source
Lemma ge0_integral_density_law (g : T -> \bar R) E : measurable E -> (forall x, 0 <= g x) -> measurable_fun E g -> \int[L]_(x in E) g x = \int[mu]_(x in E) (g x * (f x)%:E).
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R] (hf : prob_density mu f) [g : T -> \bar R] [E : set T], d.-measurable E -> measurable_fun E g -> (density_law mu f hf).-integrable E g <-> mu.-integrable E (fun x : T => (g x * (f x)%:E)%E)
Statement as written in the source
Lemma integrable_density_law (g : T -> \bar R) E : measurable E -> measurable_fun E g -> L.-integrable E g <-> mu.-integrable E (fun x => g x * (f x)%:E).
Used by 1 declaration in 1 file
- this file: integral_density_law
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f : T -> R] [hf : prob_density mu f] [g : T -> \bar R] [E : set T], d.-measurable E -> (density_law mu f hf).-integrable E g -> (\int[density_law mu f hf]_(x in E) g x)%E = (\int[mu]_(x in E) (g x * (f x)%:E))%E
Statement as written in the source
Lemma integral_density_law (g : T -> \bar R) E : measurable E -> L.-integrable E g -> \int[L]_(x in E) g x = \int[mu]_(x in E) (g x * (f x)%:E).
forall [d : measure_display] [T : measurableType d] [R : realType] [mu : probability T R] [f f' : T -> R] (hf : prob_density mu f) (hf' : prob_density mu f'), ae_eq mu [set: T] (fun x : T => (f x)%:E) (fun x : T => (f' x)%:E) -> forall [A : set T], d.-measurable A -> density_law mu f hf A = density_law mu f' hf' A
Statement as written in the source
Lemma eq_density_law d (T : measurableType d) (R : realType) (mu : probability T R) (f f' : T -> R) (hf : prob_density mu f) (hf' : prob_density mu f') : ae_eq mu [set: T] (fun x => (f x)%:E) (fun x => (f' x)%:E) -> forall A, measurable A -> density_law mu f hf A = density_law mu f' hf' A.
Context d (T : measurableType d) (R : realType). Local Open Scope ereal_scope.
forall [d : measure_display] [T : measurableType d] (R : realType) [n : nat] (A : 'I_n -> set T) (x : n.-tuple T), \1_(tuple_box A) x = \prod_(k < n) \1_(A k) (tnth x k)
The indicator of a box is the product of the indicators of its sides.
Stated in the README together with prob_density_tuple_prod.
Statement as written in the source
Lemma indic_tuple_box n (A : 'I_n -> set T) (x : n.-tuple T) : (\1_(tuple_box A) x = \prod_(k < n) \1_(A k) (tnth x k) :> R)%R.
Used by 1 declaration in 1 file
- this file: tuple_prod_density
forall [d : measure_display] [T : measurableType d] [R : realType] [nu : nat -> probability T R] [f : nat -> T -> R] [n : nat], (forall k : nat, (k < n)%N -> prob_density (nu k) (f k)) -> prob_density (tuple_prod nu n) (fun x : n.-tuple T => \prod_(k < n) f k (tnth x k))
If f_k is a density against nu_k for every k < n, the product of the laws density_prob nu_k f_k has the density x |-> prod_k f_k (x_k) against tuple_prod nu n.
Statement as written in the source
Lemma prob_density_tuple_prod (nu : nat -> probability T R) (f : nat -> T -> R) n : (forall k, (k < n)%N -> prob_density (nu k) (f k)) -> prob_density (tuple_prod nu n) (fun x => \prod_(k < n) f k (tnth x k))%R.
Used by 1 declaration in 1 file
- this file: tuple_prod_density
forall [d : measure_display] [T : measurableType d] [R : realType] [nu : nat -> probability T R] [f : nat -> T -> R] [n : nat] [E : set (n.-tuple T)], (forall k : nat, (k < n)%N -> prob_density (nu k) (f k)) -> (measure_tuple_display d).-measurable E -> tuple_prod (fun k : nat => density_prob (nu k) (f k)) n E = (\int[tuple_prod nu n]_(x in E) (\prod_(k < n) f k (tnth x k))%:E)%E
Stated in the README together with prob_density_tuple_prod.
Statement as written in the source
Lemma tuple_prod_density (nu : nat -> probability T R) (f : nat -> T -> R) n E : (forall k, (k < n)%N -> prob_density (nu k) (f k)) -> measurable E -> tuple_prod (fun k => density_prob (nu k) (f k)) n E = \int[tuple_prod nu n]_(x in E) (\prod_(k < n) f k (tnth x k))%:E.
Used by 1 declaration in 1 file
- this file: tuple_prod_density_law
forall [d : measure_display] [T : measurableType d] [R : realType] [nu : nat -> probability T R] [f : nat -> T -> R] (hf : forall k : nat, prob_density (nu k) (f k)) [n : nat] [E : set (n.-tuple T)], (measure_tuple_display d).-measurable E -> tuple_prod (fun k : nat => density_law (nu k) (f k) (hf k)) n E = (\int[tuple_prod nu n]_(x in E) (\prod_(k < n) f k (tnth x k))%:E)%E
Statement as written in the source
Lemma tuple_prod_density_law (nu : nat -> probability T R) (f : nat -> T -> R) (hf : forall k, prob_density (nu k) (f k)) n E : measurable E -> tuple_prod (fun k => density_law (nu k) (f k) (hf k)) n E = \int[tuple_prod nu n]_(x in E) (\prod_(k < n) f k (tnth x k))%:E.