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to_measure_of_fintype_apply [measurable_space α] (hs : measurable_set s) : (of_fintype f h).to_measure s = ∑' x, s.indicator f x
(to_measure_apply_eq_to_outer_measure_apply _ s hs).trans (to_outer_measure_of_fintype_apply h s)
lemma
pmf.to_measure_of_fintype_apply
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "measurable_set", "measurable_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
normalize (f : α → ℝ≥0∞) (hf0 : tsum f ≠ 0) (hf : tsum f ≠ ∞) : pmf α
⟨λ a, f a * (∑' x, f x)⁻¹, ennreal.summable.has_sum_iff.2 (ennreal.tsum_mul_right.trans (ennreal.mul_inv_cancel hf0 hf))⟩
def
pmf.normalize
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "ennreal.mul_inv_cancel", "normalize", "pmf", "tsum" ]
Given a `f` with non-zero and non-infinite sum, get a `pmf` by normalizing `f` by its `tsum`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
normalize_apply (a : α) : (normalize f hf0 hf) a = f a * (∑' x, f x)⁻¹
rfl
lemma
pmf.normalize_apply
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "normalize", "normalize_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
support_normalize : (normalize f hf0 hf).support = function.support f
set.ext (λ a, by simp [hf, mem_support_iff])
lemma
pmf.support_normalize
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "function.support", "normalize", "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_support_normalize_iff (a : α) : a ∈ (normalize f hf0 hf).support ↔ f a ≠ 0
by simp
lemma
pmf.mem_support_normalize_iff
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "normalize" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter (p : pmf α) (s : set α) (h : ∃ a ∈ s, a ∈ p.support) : pmf α
pmf.normalize (s.indicator p) (by simpa using h) (p.tsum_coe_indicator_ne_top s)
def
pmf.filter
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "filter", "pmf", "pmf.normalize" ]
Create new `pmf` by filtering on a set with non-zero measure and normalizing
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter_apply (a : α) : (p.filter s h) a = (s.indicator p a) * (∑' a', (s.indicator p) a')⁻¹
by rw [filter, normalize_apply]
lemma
pmf.filter_apply
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "filter", "normalize_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter_apply_eq_zero_of_not_mem {a : α} (ha : a ∉ s) : (p.filter s h) a = 0
by rw [filter_apply, set.indicator_apply_eq_zero.mpr (λ ha', absurd ha' ha), zero_mul]
lemma
pmf.filter_apply_eq_zero_of_not_mem
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_support_filter_iff {a : α} : a ∈ (p.filter s h).support ↔ a ∈ s ∧ a ∈ p.support
(mem_support_normalize_iff _ _ _).trans set.indicator_apply_ne_zero
lemma
pmf.mem_support_filter_iff
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
support_filter : (p.filter s h).support = s ∩ p.support
set.ext $ λ x, (mem_support_filter_iff _)
lemma
pmf.support_filter
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter_apply_eq_zero_iff (a : α) : (p.filter s h) a = 0 ↔ a ∉ s ∨ a ∉ p.support
by erw [apply_eq_zero_iff, support_filter, set.mem_inter_iff, not_and_distrib]
lemma
pmf.filter_apply_eq_zero_iff
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "not_and_distrib", "set.mem_inter_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter_apply_ne_zero_iff (a : α) : (p.filter s h) a ≠ 0 ↔ a ∈ s ∧ a ∈ p.support
by rw [ne.def, filter_apply_eq_zero_iff, not_or_distrib, not_not, not_not]
lemma
pmf.filter_apply_ne_zero_iff
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "not_not", "not_or_distrib" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bernoulli (p : ℝ≥0∞) (h : p ≤ 1) : pmf bool
of_fintype (λ b, cond b p (1 - p)) (by simp [h])
def
pmf.bernoulli
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "bernoulli", "pmf" ]
A `pmf` which assigns probability `p` to `tt` and `1 - p` to `ff`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bernoulli_apply : bernoulli p h b = cond b p (1 - p)
rfl
lemma
pmf.bernoulli_apply
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "bernoulli" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
support_bernoulli : (bernoulli p h).support = {b | cond b (p ≠ 0) (p ≠ 1)}
begin refine set.ext (λ b, _), induction b, { simp_rw [mem_support_iff, bernoulli_apply, bool.cond_ff, ne.def, tsub_eq_zero_iff_le, not_le], exact ⟨ne_of_lt, lt_of_le_of_ne h⟩ }, { simp only [mem_support_iff, bernoulli_apply, bool.cond_tt, set.mem_set_of_eq], } end
lemma
pmf.support_bernoulli
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "bernoulli", "bool.cond_ff", "bool.cond_tt", "set.ext", "tsub_eq_zero_iff_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_support_bernoulli_iff : b ∈ (bernoulli p h).support ↔ cond b (p ≠ 0) (p ≠ 1)
by simp
lemma
pmf.mem_support_bernoulli_iff
probability.probability_mass_function
src/probability/probability_mass_function/constructions.lean
[ "probability.probability_mass_function.monad" ]
[ "bernoulli" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pure (a : α) : pmf α
⟨λ a', if a' = a then 1 else 0, has_sum_ite_eq _ _⟩
def
pmf.pure
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "has_sum_ite_eq", "pmf" ]
The pure `pmf` is the `pmf` where all the mass lies in one point. The value of `pure a` is `1` at `a` and `0` elsewhere.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pure_apply : pure a a' = (if a' = a then 1 else 0)
rfl
lemma
pmf.pure_apply
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
support_pure : (pure a).support = {a}
set.ext (λ a', by simp [mem_support_iff])
lemma
pmf.support_pure
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_support_pure_iff: a' ∈ (pure a).support ↔ a' = a
by simp
lemma
pmf.mem_support_pure_iff
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pure_apply_self : pure a a = 1
if_pos rfl
lemma
pmf.pure_apply_self
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pure_apply_of_ne (h : a' ≠ a) : pure a a' = 0
if_neg h
lemma
pmf.pure_apply_of_ne
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_outer_measure_pure_apply : (pure a).to_outer_measure s = if a ∈ s then 1 else 0
begin refine (to_outer_measure_apply (pure a) s).trans _, split_ifs with ha ha, { refine ((tsum_congr (λ b, _)).trans (tsum_ite_eq a 1)), exact ite_eq_left_iff.2 (λ hb, symm (ite_eq_right_iff.2 (λ h, (hb $ h.symm ▸ ha).elim))) }, { refine ((tsum_congr (λ b, _)).trans (tsum_zero)), exact ite_eq_right_iff...
lemma
pmf.to_outer_measure_pure_apply
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "tsum_congr", "tsum_ite_eq", "tsum_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_measure_pure_apply (hs : measurable_set s) : (pure a).to_measure s = if a ∈ s then 1 else 0
(to_measure_apply_eq_to_outer_measure_apply (pure a) s hs).trans (to_outer_measure_pure_apply a s)
lemma
pmf.to_measure_pure_apply
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "measurable_set" ]
The measure of a set under `pure a` is `1` for sets containing `a` and `0` otherwise
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_measure_pure : (pure a).to_measure = measure.dirac a
measure.ext (λ s hs, by simpa only [to_measure_pure_apply a s hs, measure.dirac_apply' a hs])
lemma
pmf.to_measure_pure
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_pmf_dirac [countable α] [h : measurable_singleton_class α] : (measure.dirac a).to_pmf = pure a
by rw [to_pmf_eq_iff_to_measure_eq, to_measure_pure]
lemma
pmf.to_pmf_dirac
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "countable", "measurable_singleton_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind (p : pmf α) (f : α → pmf β) : pmf β
⟨λ b, ∑' a, p a * f a b, ennreal.summable.has_sum_iff.2 (ennreal.tsum_comm.trans $ by simp only [ennreal.tsum_mul_left, tsum_coe, mul_one])⟩
def
pmf.bind
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "ennreal.tsum_mul_left", "mul_one", "pmf" ]
The monadic bind operation for `pmf`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_apply (b : β) : p.bind f b = ∑'a, p a * f a b
rfl
lemma
pmf.bind_apply
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
support_bind : (p.bind f).support = ⋃ a ∈ p.support, (f a).support
set.ext (λ b, by simp [mem_support_iff, ennreal.tsum_eq_zero, not_or_distrib])
lemma
pmf.support_bind
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "ennreal.tsum_eq_zero", "not_or_distrib", "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_support_bind_iff (b : β) : b ∈ (p.bind f).support ↔ ∃ a ∈ p.support, b ∈ (f a).support
by simp only [support_bind, set.mem_Union, set.mem_set_of_eq]
lemma
pmf.mem_support_bind_iff
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "set.mem_Union" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pure_bind (a : α) (f : α → pmf β) : (pure a).bind f = f a
have ∀ b a', ite (a' = a) 1 0 * f a' b = ite (a' = a) (f a b) 0, from assume b a', by split_ifs; simp; subst h; simp, by ext b; simp [this]
lemma
pmf.pure_bind
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "pmf" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_pure : p.bind pure = p
pmf.ext (λ x, (bind_apply _ _ _).trans (trans (tsum_eq_single x $ (λ y hy, by rw [pure_apply_of_ne _ _ hy.symm, mul_zero])) $ by rw [pure_apply_self, mul_one]))
lemma
pmf.bind_pure
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "mul_one", "mul_zero", "pmf.ext", "tsum_eq_single" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_const (p : pmf α) (q : pmf β) : p.bind (λ _, q) = q
pmf.ext (λ x, by rw [bind_apply, ennreal.tsum_mul_right, tsum_coe, one_mul])
lemma
pmf.bind_const
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "ennreal.tsum_mul_right", "one_mul", "pmf", "pmf.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_bind : (p.bind f).bind g = p.bind (λ a, (f a).bind g)
pmf.ext (λ b, by simpa only [ennreal.coe_eq_coe.symm, bind_apply, ennreal.tsum_mul_left.symm, ennreal.tsum_mul_right.symm, mul_assoc, mul_left_comm, mul_comm] using ennreal.tsum_comm)
lemma
pmf.bind_bind
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "ennreal.tsum_comm", "mul_assoc", "mul_comm", "mul_left_comm", "pmf.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_comm (p : pmf α) (q : pmf β) (f : α → β → pmf γ) : p.bind (λ a, q.bind (f a)) = q.bind (λ b, p.bind (λ a, f a b))
pmf.ext (λ b, by simpa only [ennreal.coe_eq_coe.symm, bind_apply, ennreal.tsum_mul_left.symm, ennreal.tsum_mul_right.symm, mul_assoc, mul_left_comm, mul_comm] using ennreal.tsum_comm)
lemma
pmf.bind_comm
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "ennreal.tsum_comm", "mul_assoc", "mul_comm", "mul_left_comm", "pmf", "pmf.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_outer_measure_bind_apply : (p.bind f).to_outer_measure s = ∑' a, p a * (f a).to_outer_measure s
calc (p.bind f).to_outer_measure s = ∑' b, if b ∈ s then ∑' a, p a * f a b else 0 : by simp [to_outer_measure_apply, set.indicator_apply] ... = ∑' b a, p a * (if b ∈ s then f a b else 0) : tsum_congr (λ b, by split_ifs; simp) ... = ∑' a b, p a * (if b ∈ s then f a b else 0) : tsum_comm' ennreal.summab...
lemma
pmf.to_outer_measure_bind_apply
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "ennreal.summable", "ennreal.tsum_mul_left", "tsum_comm'", "tsum_congr" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_measure_bind_apply [measurable_space β] (hs : measurable_set s) : (p.bind f).to_measure s = ∑' a, p a * (f a).to_measure s
(to_measure_apply_eq_to_outer_measure_apply (p.bind f) s hs).trans ((to_outer_measure_bind_apply p f s).trans (tsum_congr (λ a, congr_arg (λ x, p a * x) (to_measure_apply_eq_to_outer_measure_apply (f a) s hs).symm)))
lemma
pmf.to_measure_bind_apply
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "measurable_set", "measurable_space", "tsum_congr" ]
The measure of a set under `p.bind f` is the sum over `a : α` of the probability of `a` under `p` times the measure of the set under `f a`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_on_support (p : pmf α) (f : Π a ∈ p.support, pmf β) : pmf β
⟨λ b, ∑' a, p a * if h : p a = 0 then 0 else f a h b, ennreal.summable.has_sum_iff.2 begin refine (ennreal.tsum_comm.trans (trans (tsum_congr $ λ a, _) p.tsum_coe)), simp_rw [ennreal.tsum_mul_left], split_ifs with h, { simp only [h, zero_mul] }, { rw [(f a h).tsum_coe, mul_one] } end⟩
def
pmf.bind_on_support
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "ennreal.tsum_mul_left", "mul_one", "pmf", "tsum_congr", "zero_mul" ]
Generalized version of `bind` allowing `f` to only be defined on the support of `p`. `p.bind f` is equivalent to `p.bind_on_support (λ a _, f a)`, see `bind_on_support_eq_bind`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_on_support_apply (b : β) : p.bind_on_support f b = ∑' a, p a * if h : p a = 0 then 0 else f a h b
rfl
lemma
pmf.bind_on_support_apply
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
support_bind_on_support : (p.bind_on_support f).support = ⋃ (a : α) (h : a ∈ p.support), (f a h).support
begin refine set.ext (λ b, _), simp only [ennreal.tsum_eq_zero, not_or_distrib, mem_support_iff, bind_on_support_apply, ne.def, not_forall, mul_eq_zero, set.mem_Union], exact ⟨λ hb, let ⟨a, ⟨ha, ha'⟩⟩ := hb in ⟨a, ha, by simpa [ha] using ha'⟩, λ hb, let ⟨a, ha, ha'⟩ := hb in ⟨a, ⟨ha, by simpa [(mem_suppor...
lemma
pmf.support_bind_on_support
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "ennreal.tsum_eq_zero", "mul_eq_zero", "not_forall", "not_or_distrib", "set.ext", "set.mem_Union" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_support_bind_on_support_iff (b : β) : b ∈ (p.bind_on_support f).support ↔ ∃ (a : α) (h : a ∈ p.support), b ∈ (f a h).support
by simp only [support_bind_on_support, set.mem_set_of_eq, set.mem_Union]
lemma
pmf.mem_support_bind_on_support_iff
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "set.mem_Union" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_on_support_eq_bind (p : pmf α) (f : α → pmf β) : p.bind_on_support (λ a _, f a) = p.bind f
begin ext b x, have : ∀ a, ite (p a = 0) 0 (p a * f a b) = p a * f a b, from λ a, ite_eq_right_iff.2 (λ h, h.symm ▸ symm (zero_mul $ f a b)), simp only [bind_on_support_apply (λ a _, f a), p.bind_apply f, dite_eq_ite, mul_ite, mul_zero, this], end
lemma
pmf.bind_on_support_eq_bind
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "dite_eq_ite", "mul_ite", "mul_zero", "pmf", "zero_mul" ]
`bind_on_support` reduces to `bind` if `f` doesn't depend on the additional hypothesis
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_on_support_eq_zero_iff (b : β) : p.bind_on_support f b = 0 ↔ ∀ a (ha : p a ≠ 0), f a ha b = 0
begin simp only [bind_on_support_apply, ennreal.tsum_eq_zero, mul_eq_zero, or_iff_not_imp_left], exact ⟨λ h a ha, trans (dif_neg ha).symm (h a ha), λ h a ha, trans (dif_neg ha) (h a ha)⟩, end
lemma
pmf.bind_on_support_eq_zero_iff
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "ennreal.tsum_eq_zero", "mul_eq_zero", "or_iff_not_imp_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pure_bind_on_support (a : α) (f : Π (a' : α) (ha : a' ∈ (pure a).support), pmf β) : (pure a).bind_on_support f = f a ((mem_support_pure_iff a a).mpr rfl)
begin refine pmf.ext (λ b, _), simp only [bind_on_support_apply, pure_apply], refine trans (tsum_congr (λ a', _)) (tsum_ite_eq a _), by_cases h : (a' = a); simp [h], end
lemma
pmf.pure_bind_on_support
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "pmf", "pmf.ext", "tsum_congr", "tsum_ite_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_on_support_pure (p : pmf α) : p.bind_on_support (λ a _, pure a) = p
by simp only [pmf.bind_pure, pmf.bind_on_support_eq_bind]
lemma
pmf.bind_on_support_pure
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "pmf", "pmf.bind_on_support_eq_bind", "pmf.bind_pure" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_on_support_bind_on_support (p : pmf α) (f : ∀ a ∈ p.support, pmf β) (g : ∀ (b ∈ (p.bind_on_support f).support), pmf γ) : (p.bind_on_support f).bind_on_support g = p.bind_on_support (λ a ha, (f a ha).bind_on_support (λ b hb, g b ((mem_support_bind_on_support_iff f b).mpr ⟨a, ha, hb⟩)))
begin refine pmf.ext (λ a, _), simp only [ennreal.coe_eq_coe.symm, bind_on_support_apply, ← tsum_dite_right, ennreal.tsum_mul_left.symm, ennreal.tsum_mul_right.symm], simp only [ennreal.tsum_eq_zero, ennreal.coe_eq_coe, ennreal.coe_eq_zero, ennreal.coe_zero, dite_eq_left_iff, mul_eq_zero], refine ennrea...
lemma
pmf.bind_on_support_bind_on_support
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "dite_eq_left_iff", "ennreal.coe_eq_coe", "ennreal.coe_eq_zero", "ennreal.coe_zero", "ennreal.tsum_eq_zero", "mul_eq_zero", "pmf", "pmf.ext", "tsum_congr", "tsum_dite_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bind_on_support_comm (p : pmf α) (q : pmf β) (f : ∀ (a ∈ p.support) (b ∈ q.support), pmf γ) : p.bind_on_support (λ a ha, q.bind_on_support (f a ha)) = q.bind_on_support (λ b hb, p.bind_on_support (λ a ha, f a ha b hb))
begin apply pmf.ext, rintro c, simp only [ennreal.coe_eq_coe.symm, bind_on_support_apply, ← tsum_dite_right, ennreal.tsum_mul_left.symm, ennreal.tsum_mul_right.symm], refine trans (ennreal.tsum_comm) (tsum_congr (λ b, tsum_congr (λ a, _))), split_ifs with h1 h2 h2; ring, end
lemma
pmf.bind_on_support_comm
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "ennreal.tsum_comm", "pmf", "pmf.ext", "ring", "tsum_congr", "tsum_dite_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_outer_measure_bind_on_support_apply : (p.bind_on_support f).to_outer_measure s = ∑' a, p a * if h : p a = 0 then 0 else (f a h).to_outer_measure s
begin simp only [to_outer_measure_apply, set.indicator_apply, bind_on_support_apply], calc ∑' b, ite (b ∈ s) (∑' a, p a * dite (p a = 0) (λ h, 0) (λ h, f a h b)) 0 = ∑' b a, ite (b ∈ s) (p a * dite (p a = 0) (λ h, 0) (λ h, f a h b)) 0 : tsum_congr (λ b, by split_ifs with hbs; simp only [eq_self_iff_true, ...
lemma
pmf.to_outer_measure_bind_on_support_apply
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "ennreal.tsum_comm", "ennreal.tsum_mul_left", "mul_ite", "mul_zero", "tsum_congr", "tsum_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_measure_bind_on_support_apply [measurable_space β] (hs : measurable_set s) : (p.bind_on_support f).to_measure s = ∑' a, p a * if h : p a = 0 then 0 else (f a h).to_measure s
by simp only [to_measure_apply_eq_to_outer_measure_apply _ _ hs, to_outer_measure_bind_on_support_apply]
lemma
pmf.to_measure_bind_on_support_apply
probability.probability_mass_function
src/probability/probability_mass_function/monad.lean
[ "probability.probability_mass_function.basic" ]
[ "measurable_set", "measurable_space" ]
The measure of a set under `p.bind_on_support f` is the sum over `a : α` of the probability of `a` under `p` times the measure of the set under `f a _`. The additional if statement is needed since `f` is only a partial function
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_of_finset (s : finset α) (hs : s.nonempty) : pmf α
of_finset (λ a, if a ∈ s then s.card⁻¹ else 0) s (Exists.rec_on hs (λ x hx, calc ∑ (a : α) in s, ite (a ∈ s) (s.card : ℝ≥0∞)⁻¹ 0 = ∑ (a : α) in s, (s.card : ℝ≥0∞)⁻¹ : finset.sum_congr rfl (λ x hx, by simp [hx]) ... = (s.card : ℝ≥0∞) * (s.card : ℝ≥0∞)⁻¹ : by rw [finset.sum_const, nsmul_eq_mul] ... = 1 : en...
def
pmf.uniform_of_finset
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "ennreal.mul_inv_cancel", "ennreal.nat_ne_top", "finset", "finset.card_eq_zero", "nat.cast_eq_zero", "nsmul_eq_mul", "pmf" ]
Uniform distribution taking the same non-zero probability on the nonempty finset `s`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_of_finset_apply (a : α) : uniform_of_finset s hs a = if a ∈ s then s.card⁻¹ else 0
rfl
lemma
pmf.uniform_of_finset_apply
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_of_finset_apply_of_mem (ha : a ∈ s) : uniform_of_finset s hs a = (s.card)⁻¹
by simp [ha]
lemma
pmf.uniform_of_finset_apply_of_mem
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_of_finset_apply_of_not_mem (ha : a ∉ s) : uniform_of_finset s hs a = 0
by simp [ha]
lemma
pmf.uniform_of_finset_apply_of_not_mem
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
support_uniform_of_finset : (uniform_of_finset s hs).support = s
set.ext (let ⟨a, ha⟩ := hs in by simp [mem_support_iff, finset.ne_empty_of_mem ha])
lemma
pmf.support_uniform_of_finset
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "finset.ne_empty_of_mem", "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_support_uniform_of_finset_iff (a : α) : a ∈ (uniform_of_finset s hs).support ↔ a ∈ s
by simp
lemma
pmf.mem_support_uniform_of_finset_iff
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_outer_measure_uniform_of_finset_apply : (uniform_of_finset s hs).to_outer_measure t = (s.filter (∈ t)).card / s.card
calc (uniform_of_finset s hs).to_outer_measure t = ∑' x, if x ∈ t then (uniform_of_finset s hs x) else 0 : to_outer_measure_apply (uniform_of_finset s hs) t ... = ∑' x, if x ∈ s ∧ x ∈ t then (s.card : ℝ≥0∞)⁻¹ else 0 : (tsum_congr (λ x, by simp only [uniform_of_finset_apply, and_comm (x ∈ s), ite_and, ...
lemma
pmf.to_outer_measure_uniform_of_finset_apply
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "div_eq_mul_inv", "ennreal.coe_nat", "finset.card_ne_zero_of_mem", "ite_and", "nsmul_eq_mul", "tsum_congr", "tsum_eq_sum" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_measure_uniform_of_finset_apply [measurable_space α] (ht : measurable_set t) : (uniform_of_finset s hs).to_measure t = (s.filter (∈ t)).card / s.card
(to_measure_apply_eq_to_outer_measure_apply _ t ht).trans (to_outer_measure_uniform_of_finset_apply hs t)
lemma
pmf.to_measure_uniform_of_finset_apply
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "measurable_set", "measurable_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_of_fintype (α : Type*) [fintype α] [nonempty α] : pmf α
uniform_of_finset (finset.univ) (finset.univ_nonempty)
def
pmf.uniform_of_fintype
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "finset.univ", "finset.univ_nonempty", "fintype", "pmf" ]
The uniform pmf taking the same uniform value on all of the fintype `α`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_of_fintype_apply (a : α) : uniform_of_fintype α a = (fintype.card α)⁻¹
by simpa only [uniform_of_fintype, finset.mem_univ, if_true, uniform_of_finset_apply]
lemma
pmf.uniform_of_fintype_apply
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "finset.mem_univ", "fintype.card" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
support_uniform_of_fintype (α : Type*) [fintype α] [nonempty α] : (uniform_of_fintype α).support = ⊤
set.ext (λ x, by simp [mem_support_iff])
lemma
pmf.support_uniform_of_fintype
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "fintype", "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_support_uniform_of_fintype (a : α) : a ∈ (uniform_of_fintype α).support
by simp
lemma
pmf.mem_support_uniform_of_fintype
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_outer_measure_uniform_of_fintype_apply : (uniform_of_fintype α).to_outer_measure s = fintype.card s / fintype.card α
by simpa [uniform_of_fintype]
lemma
pmf.to_outer_measure_uniform_of_fintype_apply
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "fintype.card" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_measure_uniform_of_fintype_apply [measurable_space α] (hs : measurable_set s) : (uniform_of_fintype α).to_measure s = fintype.card s / fintype.card α
by simpa [uniform_of_fintype, hs]
lemma
pmf.to_measure_uniform_of_fintype_apply
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "fintype.card", "measurable_set", "measurable_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_multiset (s : multiset α) (hs : s ≠ 0) : pmf α
⟨λ a, s.count a / s.card, ennreal.summable.has_sum_iff.2 (calc ∑' (b : α), (s.count b : ℝ≥0∞) / s.card = s.card⁻¹ * ∑' b, s.count b : by simp_rw [ennreal.div_eq_inv_mul, ennreal.tsum_mul_left] ... = s.card⁻¹ * ∑ b in s.to_finset, (s.count b : ℝ≥0∞) : congr_arg (λ x, s.card⁻¹ * x) (tsum_eq_sum $ λ a ha...
def
pmf.of_multiset
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "ennreal.div_eq_inv_mul", "ennreal.inv_mul_cancel", "ennreal.nat_ne_top", "ennreal.tsum_mul_left", "multiset", "multiset.count_eq_zero", "multiset.mem_to_finset", "multiset.to_finset_sum_count_eq", "nat.cast_sum", "pmf", "tsum_eq_sum" ]
Given a non-empty multiset `s` we construct the `pmf` which sends `a` to the fraction of elements in `s` that are `a`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_multiset_apply (a : α) : of_multiset s hs a = s.count a / s.card
rfl
lemma
pmf.of_multiset_apply
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
support_of_multiset : (of_multiset s hs).support = s.to_finset
set.ext (by simp [mem_support_iff, hs])
lemma
pmf.support_of_multiset
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_support_of_multiset_iff (a : α) : a ∈ (of_multiset s hs).support ↔ a ∈ s.to_finset
by simp
lemma
pmf.mem_support_of_multiset_iff
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_multiset_apply_of_not_mem {a : α} (ha : a ∉ s) : of_multiset s hs a = 0
by simpa only [of_multiset_apply, ennreal.div_zero_iff, nat.cast_eq_zero, multiset.count_eq_zero, ennreal.nat_ne_top, or_false] using ha
lemma
pmf.of_multiset_apply_of_not_mem
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "ennreal.div_zero_iff", "ennreal.nat_ne_top", "multiset.count_eq_zero", "nat.cast_eq_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_outer_measure_of_multiset_apply : (of_multiset s hs).to_outer_measure t = (∑' x, (s.filter (∈ t)).count x) / s.card
begin rw [div_eq_mul_inv, ← ennreal.tsum_mul_right, to_outer_measure_apply], refine tsum_congr (λ x, _), by_cases hx : x ∈ t; simp [set.indicator, hx, div_eq_mul_inv], end
lemma
pmf.to_outer_measure_of_multiset_apply
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "div_eq_mul_inv", "ennreal.tsum_mul_right", "set.indicator", "tsum_congr" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_measure_of_multiset_apply [measurable_space α] (ht : measurable_set t) : (of_multiset s hs).to_measure t = (∑' x, (s.filter (∈ t)).count x) / s.card
(to_measure_apply_eq_to_outer_measure_apply _ t ht).trans (to_outer_measure_of_multiset_apply hs t)
lemma
pmf.to_measure_of_multiset_apply
probability.probability_mass_function
src/probability/probability_mass_function/uniform.lean
[ "probability.probability_mass_function.constructions" ]
[ "measurable_set", "measurable_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
adapted (f : filtration ι m) (u : ι → Ω → β) : Prop
∀ i : ι, strongly_measurable[f i] (u i)
def
measure_theory.adapted
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[]
A sequence of functions `u` is adapted to a filtration `f` if for all `i`, `u i` is `f i`-measurable.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul [has_mul β] [has_continuous_mul β] (hu : adapted f u) (hv : adapted f v) : adapted f (u * v)
λ i, (hu i).mul (hv i)
lemma
measure_theory.adapted.mul
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "has_continuous_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div [has_div β] [has_continuous_div β] (hu : adapted f u) (hv : adapted f v) : adapted f (u / v)
λ i, (hu i).div (hv i)
lemma
measure_theory.adapted.div
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "has_continuous_div" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv [group β] [topological_group β] (hu : adapted f u) : adapted f u⁻¹
λ i, (hu i).inv
lemma
measure_theory.adapted.inv
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "group", "topological_group" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul [has_smul ℝ β] [has_continuous_smul ℝ β] (c : ℝ) (hu : adapted f u) : adapted f (c • u)
λ i, (hu i).const_smul c
lemma
measure_theory.adapted.smul
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "has_continuous_smul", "has_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
strongly_measurable {i : ι} (hf : adapted f u) : strongly_measurable[m] (u i)
(hf i).mono (f.le i)
lemma
measure_theory.adapted.strongly_measurable
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
strongly_measurable_le {i j : ι} (hf : adapted f u) (hij : i ≤ j) : strongly_measurable[f j] (u i)
(hf i).mono (f.mono hij)
lemma
measure_theory.adapted.strongly_measurable_le
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
adapted_const (f : filtration ι m) (x : β) : adapted f (λ _ _, x)
λ i, strongly_measurable_const
lemma
measure_theory.adapted_const
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
adapted_zero [has_zero β] (f : filtration ι m) : adapted f (0 : ι → Ω → β)
λ i, @strongly_measurable_zero Ω β (f i) _ _
lemma
measure_theory.adapted_zero
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filtration.adapted_natural [metrizable_space β] [mβ : measurable_space β] [borel_space β] {u : ι → Ω → β} (hum : ∀ i, strongly_measurable[m] (u i)) : adapted (filtration.natural u hum) u
begin assume i, refine strongly_measurable.mono _ (le_supr₂_of_le i (le_refl i) le_rfl), rw strongly_measurable_iff_measurable_separable, exact ⟨measurable_iff_comap_le.2 le_rfl, (hum i).is_separable_range⟩ end
lemma
measure_theory.filtration.adapted_natural
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "borel_space", "le_rfl", "le_supr₂_of_le", "measurable_space", "strongly_measurable_iff_measurable_separable" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prog_measurable [measurable_space ι] (f : filtration ι m) (u : ι → Ω → β) : Prop
∀ i, strongly_measurable[subtype.measurable_space.prod (f i)] (λ p : set.Iic i × Ω, u p.1 p.2)
def
measure_theory.prog_measurable
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "measurable_space", "set.Iic" ]
Progressively measurable process. A sequence of functions `u` is said to be progressively measurable with respect to a filtration `f` if at each point in time `i`, `u` restricted to `set.Iic i × Ω` is measurable with respect to the product `measurable_space` structure where the σ-algebra used for `Ω` is `f i`. The usua...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prog_measurable_const [measurable_space ι] (f : filtration ι m) (b : β) : prog_measurable f ((λ _ _, b) : ι → Ω → β)
λ i, @strongly_measurable_const _ _ (subtype.measurable_space.prod (f i)) _ _
lemma
measure_theory.prog_measurable_const
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "measurable_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
adapted (h : prog_measurable f u) : adapted f u
begin intro i, have : u i = (λ p : set.Iic i × Ω, u p.1 p.2) ∘ (λ x, (⟨i, set.mem_Iic.mpr le_rfl⟩, x)) := rfl, rw this, exact (h i).comp_measurable measurable_prod_mk_left, end
lemma
measure_theory.prog_measurable.adapted
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "measurable_prod_mk_left", "set.Iic" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp {t : ι → Ω → ι} [topological_space ι] [borel_space ι] [metrizable_space ι] (h : prog_measurable f u) (ht : prog_measurable f t) (ht_le : ∀ i ω, t i ω ≤ i) : prog_measurable f (λ i ω, u (t i ω) ω)
begin intro i, have : (λ p : ↥(set.Iic i) × Ω, u (t (p.fst : ι) p.snd) p.snd) = (λ p : ↥(set.Iic i) × Ω, u (p.fst : ι) p.snd) ∘ (λ p : ↥(set.Iic i) × Ω, (⟨t (p.fst : ι) p.snd, set.mem_Iic.mpr ((ht_le _ _).trans p.fst.prop)⟩, p.snd)) := rfl, rw this, exact (h i).comp_measurable ((ht i).measurable.subty...
lemma
measure_theory.prog_measurable.comp
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "borel_space", "measurable_snd", "set.Iic", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul [has_mul β] [has_continuous_mul β] (hu : prog_measurable f u) (hv : prog_measurable f v) : prog_measurable f (λ i ω, u i ω * v i ω)
λ i, (hu i).mul (hv i)
lemma
measure_theory.prog_measurable.mul
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "has_continuous_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
finset_prod' {γ} [comm_monoid β] [has_continuous_mul β] {U : γ → ι → Ω → β} {s : finset γ} (h : ∀ c ∈ s, prog_measurable f (U c)) : prog_measurable f (∏ c in s, U c)
finset.prod_induction U (prog_measurable f) (λ _ _, prog_measurable.mul) (prog_measurable_const _ 1) h
lemma
measure_theory.prog_measurable.finset_prod'
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "comm_monoid", "finset", "finset.prod_induction", "has_continuous_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
finset_prod {γ} [comm_monoid β] [has_continuous_mul β] {U : γ → ι → Ω → β} {s : finset γ} (h : ∀ c ∈ s, prog_measurable f (U c)) : prog_measurable f (λ i a, ∏ c in s, U c i a)
by { convert prog_measurable.finset_prod' h, ext i a, simp only [finset.prod_apply], }
lemma
measure_theory.prog_measurable.finset_prod
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "comm_monoid", "finset", "finset.prod_apply", "has_continuous_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv [group β] [topological_group β] (hu : prog_measurable f u) : prog_measurable f (λ i ω, (u i ω)⁻¹)
λ i, (hu i).inv
lemma
measure_theory.prog_measurable.inv
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "group", "topological_group" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div [group β] [topological_group β] (hu : prog_measurable f u) (hv : prog_measurable f v) : prog_measurable f (λ i ω, u i ω / v i ω)
λ i, (hu i).div (hv i)
lemma
measure_theory.prog_measurable.div
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "group", "topological_group" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prog_measurable_of_tendsto' {γ} [measurable_space ι] [pseudo_metrizable_space β] (fltr : filter γ) [fltr.ne_bot] [fltr.is_countably_generated] {U : γ → ι → Ω → β} (h : ∀ l, prog_measurable f (U l)) (h_tendsto : tendsto U fltr (𝓝 u)) : prog_measurable f u
begin assume i, apply @strongly_measurable_of_tendsto (set.Iic i × Ω) β γ (measurable_space.prod _ (f i)) _ _ fltr _ _ _ _ (λ l, h l i), rw tendsto_pi_nhds at h_tendsto ⊢, intro x, specialize h_tendsto x.fst, rw tendsto_nhds at h_tendsto ⊢, exact λ s hs h_mem, h_tendsto {g | g x.snd ∈ s} (hs.preimage (...
lemma
measure_theory.prog_measurable_of_tendsto'
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "continuous_apply", "filter", "measurable_space", "measurable_space.prod", "set.Iic", "strongly_measurable_of_tendsto", "tendsto_nhds", "tendsto_pi_nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prog_measurable_of_tendsto [measurable_space ι] [pseudo_metrizable_space β] {U : ℕ → ι → Ω → β} (h : ∀ l, prog_measurable f (U l)) (h_tendsto : tendsto U at_top (𝓝 u)) : prog_measurable f u
prog_measurable_of_tendsto' at_top h h_tendsto
lemma
measure_theory.prog_measurable_of_tendsto
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "measurable_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
adapted.prog_measurable_of_continuous [topological_space ι] [metrizable_space ι] [second_countable_topology ι] [measurable_space ι] [opens_measurable_space ι] [pseudo_metrizable_space β] (h : adapted f u) (hu_cont : ∀ ω, continuous (λ i, u i ω)) : prog_measurable f u
λ i, @strongly_measurable_uncurry_of_continuous_of_strongly_measurable _ _ (set.Iic i) _ _ _ _ _ _ _ (f i) _ (λ ω, (hu_cont ω).comp continuous_induced_dom) (λ j, (h j).mono (f.mono j.prop))
theorem
measure_theory.adapted.prog_measurable_of_continuous
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "continuous", "continuous_induced_dom", "measurable_space", "opens_measurable_space", "set.Iic", "topological_space" ]
A continuous and adapted process is progressively measurable.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
adapted.prog_measurable_of_discrete [topological_space ι] [discrete_topology ι] [second_countable_topology ι] [measurable_space ι] [opens_measurable_space ι] [pseudo_metrizable_space β] (h : adapted f u) : prog_measurable f u
h.prog_measurable_of_continuous (λ _, continuous_of_discrete_topology)
lemma
measure_theory.adapted.prog_measurable_of_discrete
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[ "continuous_of_discrete_topology", "discrete_topology", "measurable_space", "opens_measurable_space", "topological_space" ]
For filtrations indexed by a discrete order, `adapted` and `prog_measurable` are equivalent. This lemma provides `adapted f u → prog_measurable f u`. See `prog_measurable.adapted` for the reverse direction, which is true more generally.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
predictable.adapted {f : filtration ℕ m} {u : ℕ → Ω → β} (hu : adapted f (λ n, u (n + 1))) (hu0 : strongly_measurable[f 0] (u 0)) : adapted f u
λ n, match n with | 0 := hu0 | n + 1 := (hu n).mono (f.mono n.le_succ) end
lemma
measure_theory.predictable.adapted
probability.process
src/probability/process/adapted.lean
[ "probability.process.filtration", "topology.instances.discrete" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filtration {Ω : Type*} (ι : Type*) [preorder ι] (m : measurable_space Ω)
(seq : ι → measurable_space Ω) (mono' : monotone seq) (le' : ∀ i : ι, seq i ≤ m)
structure
measure_theory.filtration
probability.process
src/probability/process/filtration.lean
[ "measure_theory.function.conditional_expectation.real" ]
[ "measurable_space", "monotone" ]
A `filtration` on a measurable space `Ω` with σ-algebra `m` is a monotone sequence of sub-σ-algebras of `m`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mono {i j : ι} (f : filtration ι m) (hij : i ≤ j) : f i ≤ f j
f.mono' hij
lemma
measure_theory.filtration.mono
probability.process
src/probability/process/filtration.lean
[ "measure_theory.function.conditional_expectation.real" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le (f : filtration ι m) (i : ι) : f i ≤ m
f.le' i
lemma
measure_theory.filtration.le
probability.process
src/probability/process/filtration.lean
[ "measure_theory.function.conditional_expectation.real" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ext {f g : filtration ι m} (h : (f : ι → measurable_space Ω) = g) : f = g
by { cases f, cases g, simp only, exact h, }
lemma
measure_theory.filtration.ext
probability.process
src/probability/process/filtration.lean
[ "measure_theory.function.conditional_expectation.real" ]
[ "measurable_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const (m' : measurable_space Ω) (hm' : m' ≤ m) : filtration ι m
⟨λ _, m', monotone_const, λ _, hm'⟩
def
measure_theory.filtration.const
probability.process
src/probability/process/filtration.lean
[ "measure_theory.function.conditional_expectation.real" ]
[ "measurable_space", "monotone_const" ]
The constant filtration which is equal to `m` for all `i : ι`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const_apply {m' : measurable_space Ω} {hm' : m' ≤ m} (i : ι) : const ι m' hm' i = m'
rfl
lemma
measure_theory.filtration.const_apply
probability.process
src/probability/process/filtration.lean
[ "measure_theory.function.conditional_expectation.real" ]
[ "measurable_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83