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set_like.homogeneous_submonoid [add_monoid ι] [monoid R] (A : ι → S) [set_like.graded_monoid A] : submonoid R
{ carrier := { a | set_like.is_homogeneous A a }, one_mem' := set_like.is_homogeneous_one A, mul_mem' := λ a b, set_like.is_homogeneous.mul }
def
set_like.homogeneous_submonoid
algebra
src/algebra/graded_monoid.lean
[ "algebra.group.inj_surj", "data.list.big_operators.basic", "data.list.fin_range", "group_theory.group_action.defs", "group_theory.submonoid.basic", "data.set_like.basic", "data.sigma.basic" ]
[ "add_monoid", "monoid", "set_like.graded_monoid", "set_like.is_homogeneous", "set_like.is_homogeneous.mul", "set_like.is_homogeneous_one", "submonoid" ]
When `A` is a `set_like.graded_monoid A`, then the homogeneous elements forms a submonoid.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ghas_smul [has_add ι]
(smul {i j} : A i → M j → M (i + j))
class
graded_monoid.ghas_smul
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[]
A graded version of `has_smul`. Scalar multiplication combines grades additively, i.e. if `a ∈ A i` and `m ∈ M j`, then `a • b` must be in `M (i + j)`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ghas_mul.to_ghas_smul [has_add ι] [ghas_mul A] : ghas_smul A A
{ smul := λ _ _, ghas_mul.mul }
instance
graded_monoid.ghas_mul.to_ghas_smul
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[]
A graded version of `has_mul.to_has_smul`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ghas_smul.to_has_smul [has_add ι] [ghas_smul A M] : has_smul (graded_monoid A) (graded_monoid M)
⟨λ (x : graded_monoid A) (y : graded_monoid M), ⟨_, ghas_smul.smul x.snd y.snd⟩⟩
instance
graded_monoid.ghas_smul.to_has_smul
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[ "graded_monoid", "has_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_smul_mk [has_add ι] [ghas_smul A M] {i j} (a : A i) (b : M j) : mk i a • mk j b = mk (i + j) (ghas_smul.smul a b)
rfl
lemma
graded_monoid.mk_smul_mk
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gmul_action [add_monoid ι] [gmonoid A] extends ghas_smul A M
(one_smul (b : graded_monoid M) : (1 : graded_monoid A) • b = b) (mul_smul (a a' : graded_monoid A) (b : graded_monoid M) : (a * a') • b = a • a' • b)
class
graded_monoid.gmul_action
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[ "add_monoid", "graded_monoid", "one_smul" ]
A graded version of `mul_action`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gmonoid.to_gmul_action [add_monoid ι] [gmonoid A] : gmul_action A A
{ one_smul := gmonoid.one_mul, mul_smul := gmonoid.mul_assoc, ..ghas_mul.to_ghas_smul _ }
instance
graded_monoid.gmonoid.to_gmul_action
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[ "add_monoid", "one_smul" ]
The graded version of `monoid.to_mul_action`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gmul_action.to_mul_action [add_monoid ι] [gmonoid A] [gmul_action A M] : mul_action (graded_monoid A) (graded_monoid M)
{ one_smul := gmul_action.one_smul, mul_smul := gmul_action.mul_smul }
instance
graded_monoid.gmul_action.to_mul_action
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[ "add_monoid", "graded_monoid", "mul_action", "one_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set_like.has_graded_smul {S R N M : Type*} [set_like S R] [set_like N M] [has_smul R M] [has_add ι] (A : ι → S) (B : ι → N) : Prop
(smul_mem : ∀ ⦃i j : ι⦄ {ai bj}, ai ∈ A i → bj ∈ B j → ai • bj ∈ B (i + j))
class
set_like.has_graded_smul
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[ "has_smul", "set_like" ]
A version of `graded_monoid.ghas_smul` for internally graded objects.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set_like.ghas_smul {S R N M : Type*} [set_like S R] [set_like N M] [has_smul R M] [has_add ι] (A : ι → S) (B : ι → N) [set_like.has_graded_smul A B] : graded_monoid.ghas_smul (λ i, A i) (λ i, B i)
{ smul := λ i j a b, ⟨(a : R) • b, set_like.has_graded_smul.smul_mem a.2 b.2⟩ }
instance
set_like.ghas_smul
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[ "graded_monoid.ghas_smul", "has_smul", "set_like", "set_like.has_graded_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set_like.coe_ghas_smul {S R N M : Type*} [set_like S R] [set_like N M] [has_smul R M] [has_add ι] (A : ι → S) (B : ι → N) [set_like.has_graded_smul A B] {i j : ι} (x : A i) (y : B j) : (@graded_monoid.ghas_smul.smul ι (λ i, A i) (λ i, B i) _ _ i j x y : M) = ((x : R) • y)
rfl
lemma
set_like.coe_ghas_smul
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[ "has_smul", "set_like", "set_like.has_graded_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set_like.has_graded_mul.to_has_graded_smul [add_monoid ι] [monoid R] {S : Type*} [set_like S R] (A : ι → S) [set_like.graded_monoid A] : set_like.has_graded_smul A A
{ smul_mem := λ i j ai bj hi hj, set_like.graded_monoid.mul_mem hi hj, }
instance
set_like.has_graded_mul.to_has_graded_smul
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[ "add_monoid", "monoid", "set_like", "set_like.graded_monoid", "set_like.has_graded_smul" ]
Internally graded version of `has_mul.to_has_smul`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set_like.is_homogeneous.graded_smul [has_add ι] [has_smul R M] {A : ι → S} {B : ι → N} [set_like.has_graded_smul A B] {a : R} {b : M} : set_like.is_homogeneous A a → set_like.is_homogeneous B b → set_like.is_homogeneous B (a • b)
| ⟨i, hi⟩ ⟨j, hj⟩ := ⟨i + j, set_like.has_graded_smul.smul_mem hi hj⟩
lemma
set_like.is_homogeneous.graded_smul
algebra
src/algebra/graded_mul_action.lean
[ "algebra.graded_monoid" ]
[ "has_smul", "set_like.has_graded_smul", "set_like.is_homogeneous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator {M} [has_zero M] (s : set α) (f : α → M) : α → M
| x := by haveI := classical.dec_pred (∈ s); exact if x ∈ s then f x else 0
def
set.indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "classical.dec_pred" ]
`indicator s f a` is `f a` if `a ∈ s`, `0` otherwise.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator (s : set α) (f : α → M) : α → M
| x := by haveI := classical.dec_pred (∈ s); exact if x ∈ s then f x else 1
def
set.mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "classical.dec_pred" ]
`mul_indicator s f a` is `f a` if `a ∈ s`, `1` otherwise.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
piecewise_eq_mul_indicator [decidable_pred (∈ s)] : s.piecewise f 1 = s.mul_indicator f
funext $ λ x, @if_congr _ _ _ _ (id _) _ _ _ _ iff.rfl rfl rfl
lemma
set.piecewise_eq_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_apply (s : set α) (f : α → M) (a : α) [decidable (a ∈ s)] : mul_indicator s f a = if a ∈ s then f a else 1
by convert rfl
lemma
set.mul_indicator_apply
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_of_mem (h : a ∈ s) (f : α → M) : mul_indicator s f a = f a
by { letI := classical.dec (a ∈ s), exact if_pos h }
lemma
set.mul_indicator_of_mem
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "classical.dec" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_of_not_mem (h : a ∉ s) (f : α → M) : mul_indicator s f a = 1
by { letI := classical.dec (a ∈ s), exact if_neg h }
lemma
set.mul_indicator_of_not_mem
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "classical.dec" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_eq_one_or_self (s : set α) (f : α → M) (a : α) : mul_indicator s f a = 1 ∨ mul_indicator s f a = f a
begin by_cases h : a ∈ s, { exact or.inr (mul_indicator_of_mem h f) }, { exact or.inl (mul_indicator_of_not_mem h f) } end
lemma
set.mul_indicator_eq_one_or_self
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_apply_eq_self : s.mul_indicator f a = f a ↔ (a ∉ s → f a = 1)
by letI := classical.dec (a ∈ s); exact ite_eq_left_iff.trans (by rw [@eq_comm _ (f a)])
lemma
set.mul_indicator_apply_eq_self
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "classical.dec" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_eq_self : s.mul_indicator f = f ↔ mul_support f ⊆ s
by simp only [funext_iff, subset_def, mem_mul_support, mul_indicator_apply_eq_self, not_imp_comm]
lemma
set.mul_indicator_eq_self
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "not_imp_comm" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_eq_self_of_superset (h1 : s.mul_indicator f = f) (h2 : s ⊆ t) : t.mul_indicator f = f
by { rw mul_indicator_eq_self at h1 ⊢, exact subset.trans h1 h2 }
lemma
set.mul_indicator_eq_self_of_superset
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_apply_eq_one : mul_indicator s f a = 1 ↔ (a ∈ s → f a = 1)
by letI := classical.dec (a ∈ s); exact ite_eq_right_iff
lemma
set.mul_indicator_apply_eq_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "classical.dec", "ite_eq_right_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_eq_one : mul_indicator s f = (λ x, 1) ↔ disjoint (mul_support f) s
by simp only [funext_iff, mul_indicator_apply_eq_one, set.disjoint_left, mem_mul_support, not_imp_not]
lemma
set.mul_indicator_eq_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "disjoint", "not_imp_not", "set.disjoint_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_eq_one' : mul_indicator s f = 1 ↔ disjoint (mul_support f) s
mul_indicator_eq_one
lemma
set.mul_indicator_eq_one'
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "disjoint" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_apply_ne_one {a : α} : s.mul_indicator f a ≠ 1 ↔ a ∈ s ∩ mul_support f
by simp only [ne.def, mul_indicator_apply_eq_one, not_imp, mem_inter_iff, mem_mul_support]
lemma
set.mul_indicator_apply_ne_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "not_imp" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_support_mul_indicator : function.mul_support (s.mul_indicator f) = s ∩ function.mul_support f
ext $ λ x, by simp [function.mem_mul_support, mul_indicator_apply_eq_one]
lemma
set.mul_support_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "function.mem_mul_support", "function.mul_support" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_of_mul_indicator_ne_one (h : mul_indicator s f a ≠ 1) : a ∈ s
not_imp_comm.1 (λ hn, mul_indicator_of_not_mem hn f) h
lemma
set.mem_of_mul_indicator_ne_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
If a multiplicative indicator function is not equal to `1` at a point, then that point is in the set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_on_mul_indicator : eq_on (mul_indicator s f) f s
λ x hx, mul_indicator_of_mem hx f
lemma
set.eq_on_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_support_mul_indicator_subset : mul_support (s.mul_indicator f) ⊆ s
λ x hx, hx.imp_symm (λ h, mul_indicator_of_not_mem h f)
lemma
set.mul_support_mul_indicator_subset
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_mul_support : mul_indicator (mul_support f) f = f
mul_indicator_eq_self.2 subset.rfl
lemma
set.mul_indicator_mul_support
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_range_comp {ι : Sort*} (f : ι → α) (g : α → M) : mul_indicator (range f) g ∘ f = g ∘ f
by letI := classical.dec_pred (∈ range f); exact piecewise_range_comp _ _ _
lemma
set.mul_indicator_range_comp
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "classical.dec_pred" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_congr (h : eq_on f g s) : mul_indicator s f = mul_indicator s g
funext $ λx, by { simp only [mul_indicator], split_ifs, { exact h h_1 }, refl }
lemma
set.mul_indicator_congr
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_univ (f : α → M) : mul_indicator (univ : set α) f = f
mul_indicator_eq_self.2 $ subset_univ _
lemma
set.mul_indicator_univ
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_empty (f : α → M) : mul_indicator (∅ : set α) f = λa, 1
mul_indicator_eq_one.2 $ disjoint_empty _
lemma
set.mul_indicator_empty
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_empty' (f : α → M) : mul_indicator (∅ : set α) f = 1
mul_indicator_empty f
lemma
set.mul_indicator_empty'
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_one (s : set α) : mul_indicator s (λx, (1:M)) = λx, (1:M)
mul_indicator_eq_one.2 $ by simp only [mul_support_one, empty_disjoint]
lemma
set.mul_indicator_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_one' {s : set α} : s.mul_indicator (1 : α → M) = 1
mul_indicator_one M s
lemma
set.mul_indicator_one'
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_mul_indicator (s t : set α) (f : α → M) : mul_indicator s (mul_indicator t f) = mul_indicator (s ∩ t) f
funext $ λx, by { simp only [mul_indicator], split_ifs, repeat {simp * at * {contextual := tt}} }
lemma
set.mul_indicator_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_inter_mul_support (s : set α) (f : α → M) : mul_indicator (s ∩ mul_support f) f = mul_indicator s f
by rw [← mul_indicator_mul_indicator, mul_indicator_mul_support]
lemma
set.mul_indicator_inter_mul_support
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_mul_indicator (h : M → β) (f : α → M) {s : set α} {x : α} [decidable_pred (∈ s)] : h (s.mul_indicator f x) = s.piecewise (h ∘ f) (const α (h 1)) x
by letI := classical.dec_pred (∈ s); convert s.apply_piecewise f (const α 1) (λ _, h)
lemma
set.comp_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "classical.dec_pred" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_comp_right {s : set α} (f : β → α) {g : α → M} {x : β} : mul_indicator (f ⁻¹' s) (g ∘ f) x = mul_indicator s g (f x)
by { simp only [mul_indicator], split_ifs; refl }
lemma
set.mul_indicator_comp_right
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_image {s : set α} {f : β → M} {g : α → β} (hg : injective g) {x : α} : mul_indicator (g '' s) f (g x) = mul_indicator s (f ∘ g) x
by rw [← mul_indicator_comp_right, preimage_image_eq _ hg]
lemma
set.mul_indicator_image
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_comp_of_one {g : M → N} (hg : g 1 = 1) : mul_indicator s (g ∘ f) = g ∘ (mul_indicator s f)
begin funext, simp only [mul_indicator], split_ifs; simp [*] end
lemma
set.mul_indicator_comp_of_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_mul_indicator_const (c : M) (f : M → N) (hf : f 1 = 1) : (λ x, f (s.mul_indicator (λ x, c) x)) = s.mul_indicator (λ x, f c)
(mul_indicator_comp_of_one hf).symm
lemma
set.comp_mul_indicator_const
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_preimage (s : set α) (f : α → M) (B : set M) : (mul_indicator s f)⁻¹' B = s.ite (f ⁻¹' B) (1 ⁻¹' B)
by letI := classical.dec_pred (∈ s); exact piecewise_preimage s f 1 B
lemma
set.mul_indicator_preimage
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "classical.dec_pred" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_one_preimage (s : set M) : t.mul_indicator 1 ⁻¹' s ∈ ({set.univ, ∅} : set (set α))
begin classical, rw [mul_indicator_one', preimage_one], split_ifs; simp end
lemma
set.mul_indicator_one_preimage
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_const_preimage_eq_union (U : set α) (s : set M) (a : M) [decidable (a ∈ s)] [decidable ((1 : M) ∈ s)] : U.mul_indicator (λ x, a) ⁻¹' s = (if a ∈ s then U else ∅) ∪ (if (1 : M) ∈ s then Uᶜ else ∅)
begin rw [mul_indicator_preimage, preimage_one, preimage_const], split_ifs; simp [← compl_eq_univ_diff] end
lemma
set.mul_indicator_const_preimage_eq_union
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_const_preimage (U : set α) (s : set M) (a : M) : U.mul_indicator (λ x, a) ⁻¹' s ∈ ({set.univ, U, Uᶜ, ∅} : set (set α))
begin classical, rw [mul_indicator_const_preimage_eq_union], split_ifs; simp end
lemma
set.mul_indicator_const_preimage
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_one_preimage [has_zero M] (U : set α) (s : set M) : U.indicator 1 ⁻¹' s ∈ ({set.univ, U, Uᶜ, ∅} : set (set α))
indicator_const_preimage _ _ 1
lemma
set.indicator_one_preimage
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_preimage_of_not_mem (s : set α) (f : α → M) {t : set M} (ht : (1:M) ∉ t) : (mul_indicator s f)⁻¹' t = f ⁻¹' t ∩ s
by simp [mul_indicator_preimage, pi.one_def, set.preimage_const_of_not_mem ht]
lemma
set.mul_indicator_preimage_of_not_mem
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "pi.one_def", "set.preimage_const_of_not_mem" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_range_mul_indicator {r : M} {s : set α} {f : α → M} : r ∈ range (mul_indicator s f) ↔ (r = 1 ∧ s ≠ univ) ∨ (r ∈ f '' s)
by simp [mul_indicator, ite_eq_iff, exists_or_distrib, eq_univ_iff_forall, and_comm, or_comm, @eq_comm _ r 1]
lemma
set.mem_range_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "exists_or_distrib", "ite_eq_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_rel_mul_indicator {r : M → M → Prop} (h1 : r 1 1) (ha : a ∈ s → r (f a) (g a)) : r (mul_indicator s f a) (mul_indicator s g a)
by { simp only [mul_indicator], split_ifs with has has, exacts [ha has, h1] }
lemma
set.mul_indicator_rel_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_union_mul_inter_apply (f : α → M) (s t : set α) (a : α) : mul_indicator (s ∪ t) f a * mul_indicator (s ∩ t) f a = mul_indicator s f a * mul_indicator t f a
by by_cases hs : a ∈ s; by_cases ht : a ∈ t; simp *
lemma
set.mul_indicator_union_mul_inter_apply
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_union_mul_inter (f : α → M) (s t : set α) : mul_indicator (s ∪ t) f * mul_indicator (s ∩ t) f = mul_indicator s f * mul_indicator t f
funext $ mul_indicator_union_mul_inter_apply f s t
lemma
set.mul_indicator_union_mul_inter
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_union_of_not_mem_inter (h : a ∉ s ∩ t) (f : α → M) : mul_indicator (s ∪ t) f a = mul_indicator s f a * mul_indicator t f a
by rw [← mul_indicator_union_mul_inter_apply f s t, mul_indicator_of_not_mem h, mul_one]
lemma
set.mul_indicator_union_of_not_mem_inter
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "mul_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_union_of_disjoint (h : disjoint s t) (f : α → M) : mul_indicator (s ∪ t) f = λa, mul_indicator s f a * mul_indicator t f a
funext $ λa, mul_indicator_union_of_not_mem_inter (λ ha, h.le_bot ha) _
lemma
set.mul_indicator_union_of_disjoint
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "disjoint" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_mul (s : set α) (f g : α → M) : mul_indicator s (λa, f a * g a) = λa, mul_indicator s f a * mul_indicator s g a
by { funext, simp only [mul_indicator], split_ifs, { refl }, rw mul_one }
lemma
set.mul_indicator_mul
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "mul_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_mul' (s : set α) (f g : α → M) : mul_indicator s (f * g) = mul_indicator s f * mul_indicator s g
mul_indicator_mul s f g
lemma
set.mul_indicator_mul'
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_compl_mul_self_apply (s : set α) (f : α → M) (a : α) : mul_indicator sᶜ f a * mul_indicator s f a = f a
classical.by_cases (λ ha : a ∈ s, by simp [ha]) (λ ha, by simp [ha])
lemma
set.mul_indicator_compl_mul_self_apply
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_compl_mul_self (s : set α) (f : α → M) : mul_indicator sᶜ f * mul_indicator s f = f
funext $ mul_indicator_compl_mul_self_apply s f
lemma
set.mul_indicator_compl_mul_self
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_self_mul_compl_apply (s : set α) (f : α → M) (a : α) : mul_indicator s f a * mul_indicator sᶜ f a = f a
classical.by_cases (λ ha : a ∈ s, by simp [ha]) (λ ha, by simp [ha])
lemma
set.mul_indicator_self_mul_compl_apply
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_self_mul_compl (s : set α) (f : α → M) : mul_indicator s f * mul_indicator sᶜ f = f
funext $ mul_indicator_self_mul_compl_apply s f
lemma
set.mul_indicator_self_mul_compl
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_mul_eq_left {f g : α → M} (h : disjoint (mul_support f) (mul_support g)) : (mul_support f).mul_indicator (f * g) = f
begin refine (mul_indicator_congr $ λ x hx, _).trans mul_indicator_mul_support, have : g x = 1, from nmem_mul_support.1 (disjoint_left.1 h hx), rw [pi.mul_apply, this, mul_one] end
lemma
set.mul_indicator_mul_eq_left
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "disjoint", "mul_one", "pi.mul_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_mul_eq_right {f g : α → M} (h : disjoint (mul_support f) (mul_support g)) : (mul_support g).mul_indicator (f * g) = g
begin refine (mul_indicator_congr $ λ x hx, _).trans mul_indicator_mul_support, have : f x = 1, from nmem_mul_support.1 (disjoint_right.1 h hx), rw [pi.mul_apply, this, one_mul] end
lemma
set.mul_indicator_mul_eq_right
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "disjoint", "one_mul", "pi.mul_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_mul_compl_eq_piecewise [decidable_pred (∈ s)] (f g : α → M) : s.mul_indicator f * sᶜ.mul_indicator g = s.piecewise f g
begin ext x, by_cases h : x ∈ s, { rw [piecewise_eq_of_mem _ _ _ h, pi.mul_apply, set.mul_indicator_of_mem h, set.mul_indicator_of_not_mem (set.not_mem_compl_iff.2 h), mul_one] }, { rw [piecewise_eq_of_not_mem _ _ _ h, pi.mul_apply, set.mul_indicator_of_not_mem h, set.mul_indicator_of_mem (set.mem_c...
lemma
set.mul_indicator_mul_compl_eq_piecewise
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "mul_one", "one_mul", "pi.mul_apply", "set.mem_compl", "set.mul_indicator_of_mem", "set.mul_indicator_of_not_mem" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_hom {α} (M) [mul_one_class M] (s : set α) : (α → M) →* (α → M)
{ to_fun := mul_indicator s, map_one' := mul_indicator_one M s, map_mul' := mul_indicator_mul s }
def
set.mul_indicator_hom
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "mul_one_class" ]
`set.mul_indicator` as a `monoid_hom`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_smul_apply (s : set α) (r : α → M) (f : α → A) (x : α) : indicator s (λ x, r x • f x) x = r x • indicator s f x
by { dunfold indicator, split_ifs, exacts [rfl, (smul_zero (r x)).symm] }
lemma
set.indicator_smul_apply
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "smul_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_smul (s : set α) (r : α → M) (f : α → A) : indicator s (λ (x : α), r x • f x) = λ (x : α), r x • indicator s f x
funext $ indicator_smul_apply s r f
lemma
set.indicator_smul
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_const_smul_apply (s : set α) (r : M) (f : α → A) (x : α) : indicator s (λ x, r • f x) x = r • indicator s f x
indicator_smul_apply s (λ x, r) f x
lemma
set.indicator_const_smul_apply
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_const_smul (s : set α) (r : M) (f : α → A) : indicator s (λ (x : α), r • f x) = λ (x : α), r • indicator s f x
funext $ indicator_const_smul_apply s r f
lemma
set.indicator_const_smul
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_inv' (s : set α) (f : α → G) : mul_indicator s (f⁻¹) = (mul_indicator s f)⁻¹
(mul_indicator_hom G s).map_inv f
lemma
set.mul_indicator_inv'
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "map_inv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_inv (s : set α) (f : α → G) : mul_indicator s (λa, (f a)⁻¹) = λa, (mul_indicator s f a)⁻¹
mul_indicator_inv' s f
lemma
set.mul_indicator_inv
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_div (s : set α) (f g : α → G) : mul_indicator s (λ a, f a / g a) = λ a, mul_indicator s f a / mul_indicator s g a
(mul_indicator_hom G s).map_div f g
lemma
set.mul_indicator_div
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "map_div" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_div' (s : set α) (f g : α → G) : mul_indicator s (f / g) = mul_indicator s f / mul_indicator s g
mul_indicator_div s f g
lemma
set.mul_indicator_div'
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_compl (s : set α) (f : α → G) : mul_indicator sᶜ f = f * (mul_indicator s f)⁻¹
eq_mul_inv_of_mul_eq $ s.mul_indicator_compl_mul_self f
lemma
set.mul_indicator_compl
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "eq_mul_inv_of_mul_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_compl {G} [add_group G] (s : set α) (f : α → G) : indicator sᶜ f = f - indicator s f
by rw [sub_eq_add_neg, indicator_compl']
lemma
set.indicator_compl
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "add_group" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_diff (h : s ⊆ t) (f : α → G) : mul_indicator (t \ s) f = mul_indicator t f * (mul_indicator s f)⁻¹
eq_mul_inv_of_mul_eq $ by { rw [pi.mul_def, ←mul_indicator_union_of_disjoint, diff_union_self, union_eq_self_of_subset_right h], exact disjoint_sdiff_self_left }
lemma
set.mul_indicator_diff
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "disjoint_sdiff_self_left", "eq_mul_inv_of_mul_eq", "pi.mul_def" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_diff {G : Type*} [add_group G] {s t : set α} (h : s ⊆ t) (f : α → G) : indicator (t \ s) f = indicator t f - indicator s f
by rw [indicator_diff' h, sub_eq_add_neg]
lemma
set.indicator_diff
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "add_group" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_mul_indicator_subset_of_eq_one [has_one N] (f : α → N) (g : α → N → M) {s t : finset α} (h : s ⊆ t) (hg : ∀ a, g a 1 = 1) : ∏ i in s, g i (f i) = ∏ i in t, g i (mul_indicator ↑s f i)
begin rw ← finset.prod_subset h _, { apply finset.prod_congr rfl, intros i hi, congr, symmetry, exact mul_indicator_of_mem hi _ }, { refine λ i hi hn, _, convert hg i, exact mul_indicator_of_not_mem hn _ } end
lemma
set.prod_mul_indicator_subset_of_eq_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "finset", "finset.prod_congr", "finset.prod_subset" ]
Consider a product of `g i (f i)` over a `finset`. Suppose `g` is a function such as `pow`, which maps a second argument of `1` to `1`. Then if `f` is replaced by the corresponding multiplicative indicator function, the `finset` may be replaced by a possibly larger `finset` without changing the value of the sum.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_mul_indicator_subset (f : α → M) {s t : finset α} (h : s ⊆ t) : ∏ i in s, f i = ∏ i in t, mul_indicator ↑s f i
prod_mul_indicator_subset_of_eq_one _ (λ a b, b) h (λ _, rfl)
lemma
set.prod_mul_indicator_subset
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "finset" ]
Taking the product of an indicator function over a possibly larger `finset` is the same as taking the original function over the original `finset`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.finset.prod_mul_indicator_eq_prod_filter (s : finset ι) (f : ι → α → M) (t : ι → set α) (g : ι → α) [decidable_pred (λ i, g i ∈ t i)]: ∏ i in s, mul_indicator (t i) (f i) (g i) = ∏ i in s.filter (λ i, g i ∈ t i), f i (g i)
begin refine (finset.prod_filter_mul_prod_filter_not s (λ i, g i ∈ t i) _).symm.trans _, refine eq.trans _ (mul_one _), exact congr_arg2 (*) (finset.prod_congr rfl $ λ x hx, mul_indicator_of_mem (finset.mem_filter.1 hx).2 _) (finset.prod_eq_one $ λ x hx, mul_indicator_of_not_mem (finset.mem_filter.1 hx).2...
lemma
finset.prod_mul_indicator_eq_prod_filter
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "congr_arg2", "finset", "finset.prod_congr", "finset.prod_eq_one", "finset.prod_filter_mul_prod_filter_not", "mul_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_finset_prod (I : finset ι) (s : set α) (f : ι → α → M) : mul_indicator s (∏ i in I, f i) = ∏ i in I, mul_indicator s (f i)
(mul_indicator_hom M s).map_prod _ _
lemma
set.mul_indicator_finset_prod
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "finset", "map_prod" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_finset_bUnion {ι} (I : finset ι) (s : ι → set α) {f : α → M} : (∀ (i ∈ I) (j ∈ I), i ≠ j → disjoint (s i) (s j)) → mul_indicator (⋃ i ∈ I, s i) f = λ a, ∏ i in I, mul_indicator (s i) f a
begin classical, refine finset.induction_on I _ _, { intro h, funext, simp }, assume a I haI ih hI, funext, rw [finset.prod_insert haI, finset.set_bUnion_insert, mul_indicator_union_of_not_mem_inter, ih _], { assume i hi j hj hij, exact hI i (finset.mem_insert_of_mem hi) j (finset.mem_insert_of_mem hj...
lemma
set.mul_indicator_finset_bUnion
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "disjoint", "exists_prop", "finset", "finset.induction_on", "finset.mem_insert_of_mem", "finset.mem_insert_self", "finset.prod_insert", "finset.set_bUnion_insert", "ih", "ne_of_mem_of_not_mem", "not_and", "not_exists" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_finset_bUnion_apply {ι} (I : finset ι) (s : ι → set α) {f : α → M} (h : ∀ (i ∈ I) (j ∈ I), i ≠ j → disjoint (s i) (s j)) (x : α) : mul_indicator (⋃ i ∈ I, s i) f x = ∏ i in I, mul_indicator (s i) f x
by rw set.mul_indicator_finset_bUnion I s h
lemma
set.mul_indicator_finset_bUnion_apply
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "disjoint", "finset", "set.mul_indicator_finset_bUnion" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_mul (s : set α) (f g : α → M) : indicator s (λa, f a * g a) = λa, indicator s f a * indicator s g a
by { funext, simp only [indicator], split_ifs, { refl }, rw mul_zero }
lemma
set.indicator_mul
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "mul_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_mul_left (s : set α) (f g : α → M) : indicator s (λa, f a * g a) a = indicator s f a * g a
by { simp only [indicator], split_ifs, { refl }, rw [zero_mul] }
lemma
set.indicator_mul_left
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_mul_right (s : set α) (f g : α → M) : indicator s (λa, f a * g a) a = f a * indicator s g a
by { simp only [indicator], split_ifs, { refl }, rw [mul_zero] }
lemma
set.indicator_mul_right
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "mul_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inter_indicator_mul {t1 t2 : set α} (f g : α → M) (x : α) : (t1 ∩ t2).indicator (λ x, f x * g x) x = t1.indicator f x * t2.indicator g x
by { rw [← set.indicator_indicator], simp [indicator] }
lemma
set.inter_indicator_mul
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inter_indicator_one {s t : set α} : (s ∩ t).indicator (1 : _ → M) = s.indicator 1 * t.indicator 1
funext (λ _, by simpa only [← inter_indicator_mul, pi.mul_apply, pi.one_apply, one_mul])
lemma
set.inter_indicator_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "one_mul", "pi.mul_apply", "pi.one_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_prod_one {s : set α} {t : set β} {x : α} {y : β} : (s ×ˢ t).indicator (1 : _ → M) (x, y) = s.indicator 1 x * t.indicator 1 y
by { classical, simp [indicator_apply, ←ite_and] }
lemma
set.indicator_prod_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_eq_zero_iff_not_mem {U : set α} {x : α} : indicator U 1 x = (0 : M) ↔ x ∉ U
by { classical, simp [indicator_apply, imp_false] }
lemma
set.indicator_eq_zero_iff_not_mem
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "imp_false" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_eq_one_iff_mem {U : set α} {x : α} : indicator U 1 x = (1 : M) ↔ x ∈ U
by { classical, simp [indicator_apply, imp_false] }
lemma
set.indicator_eq_one_iff_mem
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "imp_false" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_one_inj {U V : set α} (h : indicator U (1 : α → M) = indicator V 1) : U = V
by { ext, simp_rw [← indicator_eq_one_iff_mem M, h] }
lemma
set.indicator_one_inj
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_apply_le' (hfg : a ∈ s → f a ≤ y) (hg : a ∉ s → 1 ≤ y) : mul_indicator s f a ≤ y
begin by_cases ha : a ∈ s, { simpa [ha] using hfg ha }, { simpa [ha] using hg ha }, end
lemma
set.mul_indicator_apply_le'
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_le' (hfg : ∀ a ∈ s, f a ≤ g a) (hg : ∀ a ∉ s, 1 ≤ g a) : mul_indicator s f ≤ g
λ a, mul_indicator_apply_le' (hfg _) (hg _)
lemma
set.mul_indicator_le'
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_mul_indicator_apply {y} (hfg : a ∈ s → y ≤ g a) (hf : a ∉ s → y ≤ 1) : y ≤ mul_indicator s g a
@mul_indicator_apply_le' α Mᵒᵈ ‹_› _ _ _ _ _ hfg hf
lemma
set.le_mul_indicator_apply
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_mul_indicator (hfg : ∀ a ∈ s, f a ≤ g a) (hf : ∀ a ∉ s, f a ≤ 1) : f ≤ mul_indicator s g
λ a, le_mul_indicator_apply (hfg _) (hf _)
lemma
set.le_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_le_mul_indicator_apply (h : a ∈ s → 1 ≤ f a) : 1 ≤ mul_indicator s f a
le_mul_indicator_apply h (λ _, le_rfl)
lemma
set.one_le_mul_indicator_apply
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "le_rfl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83