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mul_indicator_empty (f : α → M) : mul_indicator (∅ : set α) f = λa, 1 := mul_indicator_eq_one.2 $ disjoint_empty _
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" ]
[]
null
135
136
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_empty' (f : α → M) : mul_indicator (∅ : set α) f = 1 := mul_indicator_empty f
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" ]
[]
null
138
139
true
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]
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" ]
[]
null
143
145
true
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
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" ]
[]
null
147
148
true
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}} }
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" ]
[]
null
152
154
true
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]
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" ]
[]
null
156
158
true
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)
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" ]
null
160
163
true
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 }
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" ]
[]
null
165
167
true
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]
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" ]
[]
null
169
171
true
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
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" ]
[]
null
173
179
true
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
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" ]
[]
null
181
183
true
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
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" ]
null
185
187
true
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
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" ]
[]
null
189
195
true
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_d...
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" ]
[]
null
197
203
true
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
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" ]
[]
null
205
211
true
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
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" ]
[]
null
213
215
true
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]
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" ]
null
217
220
true
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]
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" ]
null
222
225
true
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] }
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" ]
[]
null
227
230
true
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 *
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" ]
[]
null
237
240
true
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
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" ]
[]
null
242
244
true
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]
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" ]
null
246
248
true
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) _
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" ]
null
250
252
true
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 }
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" ]
null
254
256
true
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
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" ]
[]
null
258
260
true
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])
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" ]
[]
null
262
264
true
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
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" ]
[]
null
266
268
true
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])
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" ]
[]
null
270
272
true
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
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" ]
[]
null
274
276
true
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]...
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" ]
null
278
285
true
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_mu...
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" ]
null
287
294
true
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_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" ]
null
296
306
true
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 }
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`.
310
314
true
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] }
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" ]
null
322
324
true
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
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" ]
[]
null
326
328
true
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
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" ]
[]
null
330
332
true
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
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" ]
[]
null
334
336
true
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
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" ]
null
343
345
true
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
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" ]
[]
null
347
349
true
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
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" ]
null
351
354
true
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
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" ]
[]
null
356
358
true
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
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" ]
null
360
362
true
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']
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" ]
null
364
366
true
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 }
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" ]
null
368
371
true
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]
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" ]
null
373
375
true
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...
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.
388
401
true
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)
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`.
414
418
true
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.t...
_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" ]
null
420
429
true
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 _ _
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" ]
null
431
433
true
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, fu...
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" ]
null
435
451
true
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
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" ]
null
453
456
true
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 }
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" ]
null
464
466
true
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] }
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" ]
null
468
470
true
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] }
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" ]
null
472
474
true
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] }
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" ]
[]
null
476
478
true
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])
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" ]
null
486
488
true
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] }
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" ]
[]
null
490
492
true
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] }
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" ]
null
496
498
true
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] }
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" ]
null
500
502
true
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] }
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" ]
[]
null
504
505
true
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
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" ]
[]
null
516
522
true
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 _)
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" ]
[]
null
524
526
true
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
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" ]
[]
null
528
530
true
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 _)
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" ]
[]
null
532
534
true
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)
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" ]
null
540
542
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_le_mul_indicator (h : ∀ a ∈ s, 1 ≤ f a) (a : α) : 1 ≤ mul_indicator s f a := one_le_mul_indicator_apply (h a)
one_le_mul_indicator (h : ∀ a ∈ s, 1 ≤ f a) (a : α) : 1 ≤ mul_indicator s f a
one_le_mul_indicator_apply (h a)
lemma
set.one_le_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
null
544
546
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_apply_le_one (h : a ∈ s → f a ≤ 1) : mul_indicator s f a ≤ 1 := mul_indicator_apply_le' h (λ _, le_rfl)
mul_indicator_apply_le_one (h : a ∈ s → f a ≤ 1) : mul_indicator s f a ≤ 1
mul_indicator_apply_le' h (λ _, le_rfl)
lemma
set.mul_indicator_apply_le_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "le_rfl" ]
null
548
549
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_le_one (h : ∀ a ∈ s, f a ≤ 1) (a : α) : mul_indicator s f a ≤ 1 := mul_indicator_apply_le_one (h a)
mul_indicator_le_one (h : ∀ a ∈ s, f a ≤ 1) (a : α) : mul_indicator s f a ≤ 1
mul_indicator_apply_le_one (h a)
lemma
set.mul_indicator_le_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
null
551
553
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_le_mul_indicator (h : f a ≤ g a) : mul_indicator s f a ≤ mul_indicator s g a := mul_indicator_rel_mul_indicator le_rfl (λ _, h)
mul_indicator_le_mul_indicator (h : f a ≤ g a) : mul_indicator s f a ≤ mul_indicator s g a
mul_indicator_rel_mul_indicator le_rfl (λ _, h)
lemma
set.mul_indicator_le_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "le_rfl" ]
null
555
557
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_le_mul_indicator_of_subset (h : s ⊆ t) (hf : ∀ a, 1 ≤ f a) (a : α) : mul_indicator s f a ≤ mul_indicator t f a := mul_indicator_apply_le' (λ ha, le_mul_indicator_apply (λ _, le_rfl) (λ hat, (hat $ h ha).elim)) (λ ha, one_le_mul_indicator_apply (λ _, hf _))
mul_indicator_le_mul_indicator_of_subset (h : s ⊆ t) (hf : ∀ a, 1 ≤ f a) (a : α) : mul_indicator s f a ≤ mul_indicator t f a
mul_indicator_apply_le' (λ ha, le_mul_indicator_apply (λ _, le_rfl) (λ hat, (hat $ h ha).elim)) (λ ha, one_le_mul_indicator_apply (λ _, hf _))
lemma
set.mul_indicator_le_mul_indicator_of_subset
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "le_rfl" ]
null
561
565
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_le_self' (hf : ∀ x ∉ s, 1 ≤ f x) : mul_indicator s f ≤ f := mul_indicator_le' (λ _ _, le_rfl) hf
mul_indicator_le_self' (hf : ∀ x ∉ s, 1 ≤ f x) : mul_indicator s f ≤ f
mul_indicator_le' (λ _ _, le_rfl) hf
lemma
set.mul_indicator_le_self'
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "le_rfl" ]
null
567
568
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_Union_apply {ι M} [complete_lattice M] [has_one M] (h1 : (⊥:M) = 1) (s : ι → set α) (f : α → M) (x : α) : mul_indicator (⋃ i, s i) f x = ⨆ i, mul_indicator (s i) f x := begin by_cases hx : x ∈ ⋃ i, s i, { rw [mul_indicator_of_mem hx], rw [mem_Union] at hx, refine le_antisymm _ (supr_le $ λ...
mul_indicator_Union_apply {ι M} [complete_lattice M] [has_one M] (h1 : (⊥:M) = 1) (s : ι → set α) (f : α → M) (x : α) : mul_indicator (⋃ i, s i) f x = ⨆ i, mul_indicator (s i) f x
begin by_cases hx : x ∈ ⋃ i, s i, { rw [mul_indicator_of_mem hx], rw [mem_Union] at hx, refine le_antisymm _ (supr_le $ λ i, mul_indicator_le_self' (λ x hx, h1 ▸ bot_le) x), rcases hx with ⟨i, hi⟩, exact le_supr_of_le i (ge_of_eq $ mul_indicator_of_mem hi _) }, { rw [mul_indicator_of_not_mem hx], ...
lemma
set.mul_indicator_Union_apply
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "bot_le", "complete_lattice", "ge_of_eq", "le_supr_of_le", "not_exists", "supr_le" ]
null
570
583
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_le_self (s : set α) (f : α → M) : mul_indicator s f ≤ f := mul_indicator_le_self' $ λ _ _, one_le _
mul_indicator_le_self (s : set α) (f : α → M) : mul_indicator s f ≤ f
mul_indicator_le_self' $ λ _ _, one_le _
lemma
set.mul_indicator_le_self
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "one_le" ]
null
591
593
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_apply_le {a : α} {s : set α} {f g : α → M} (hfg : a ∈ s → f a ≤ g a) : mul_indicator s f a ≤ g a := mul_indicator_apply_le' hfg $ λ _, one_le _
mul_indicator_apply_le {a : α} {s : set α} {f g : α → M} (hfg : a ∈ s → f a ≤ g a) : mul_indicator s f a ≤ g a
mul_indicator_apply_le' hfg $ λ _, one_le _
lemma
set.mul_indicator_apply_le
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "one_le" ]
null
595
598
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_indicator_le {s : set α} {f g : α → M} (hfg : ∀ a ∈ s, f a ≤ g a) : mul_indicator s f ≤ g := mul_indicator_le' hfg $ λ _ _, one_le _
mul_indicator_le {s : set α} {f g : α → M} (hfg : ∀ a ∈ s, f a ≤ g a) : mul_indicator s f ≤ g
mul_indicator_le' hfg $ λ _ _, one_le _
lemma
set.mul_indicator_le
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "one_le" ]
null
600
602
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_le_indicator_nonneg {β} [linear_order β] [has_zero β] (s : set α) (f : α → β) : s.indicator f ≤ {x | 0 ≤ f x}.indicator f := begin intro x, classical, simp_rw indicator_apply, split_ifs, { exact le_rfl, }, { exact (not_le.mp h_1).le, }, { exact h_1, }, { exact le_rfl, }, end
indicator_le_indicator_nonneg {β} [linear_order β] [has_zero β] (s : set α) (f : α → β) : s.indicator f ≤ {x | 0 ≤ f x}.indicator f
begin intro x, classical, simp_rw indicator_apply, split_ifs, { exact le_rfl, }, { exact (not_le.mp h_1).le, }, { exact h_1, }, { exact le_rfl, }, end
lemma
set.indicator_le_indicator_nonneg
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "le_rfl" ]
null
606
617
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indicator_nonpos_le_indicator {β} [linear_order β] [has_zero β] (s : set α) (f : α → β) : {x | f x ≤ 0}.indicator f ≤ s.indicator f := @indicator_le_indicator_nonneg α βᵒᵈ _ _ s f
indicator_nonpos_le_indicator {β} [linear_order β] [has_zero β] (s : set α) (f : α → β) : {x | f x ≤ 0}.indicator f ≤ s.indicator f
@indicator_le_indicator_nonneg α βᵒᵈ _ _ s f
lemma
set.indicator_nonpos_le_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
null
619
621
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
monoid_hom.map_mul_indicator {M N : Type*} [mul_one_class M] [mul_one_class N] (f : M →* N) (s : set α) (g : α → M) (x : α) : f (s.mul_indicator g x) = s.mul_indicator (f ∘ g) x := congr_fun (set.mul_indicator_comp_of_one f.map_one).symm x
monoid_hom.map_mul_indicator {M N : Type*} [mul_one_class M] [mul_one_class N] (f : M →* N) (s : set α) (g : α → M) (x : α) : f (s.mul_indicator g x) = s.mul_indicator (f ∘ g) x
congr_fun (set.mul_indicator_comp_of_one f.map_one).symm x
lemma
monoid_hom.map_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "mul_one_class", "set.mul_indicator_comp_of_one" ]
null
625
629
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible [has_mul α] [has_one α] (a : α) : Type u := (inv_of : α) (inv_of_mul_self : inv_of * a = 1) (mul_inv_of_self : a * inv_of = 1)
invertible [has_mul α] [has_one α] (a : α) : Type u
(inv_of : α) (inv_of_mul_self : inv_of * a = 1) (mul_inv_of_self : a * inv_of = 1)
class
invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_mul_self", "mul_inv_of_self" ]
`invertible a` gives a two-sided multiplicative inverse of `a`.
68
69
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_mul_self [has_mul α] [has_one α] (a : α) [invertible a] : ⅟a * a = 1 := invertible.inv_of_mul_self
inv_of_mul_self [has_mul α] [has_one α] (a : α) [invertible a] : ⅟a * a = 1
invertible.inv_of_mul_self
lemma
inv_of_mul_self
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible" ]
null
74
76
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_inv_of_self [has_mul α] [has_one α] (a : α) [invertible a] : a * ⅟a = 1 := invertible.mul_inv_of_self
mul_inv_of_self [has_mul α] [has_one α] (a : α) [invertible a] : a * ⅟a = 1
invertible.mul_inv_of_self
lemma
mul_inv_of_self
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible" ]
null
78
80
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_mul_self_assoc [monoid α] (a b : α) [invertible a] : ⅟a * (a * b) = b := by rw [←mul_assoc, inv_of_mul_self, one_mul]
inv_of_mul_self_assoc [monoid α] (a b : α) [invertible a] : ⅟a * (a * b) = b
by rw [←mul_assoc, inv_of_mul_self, one_mul]
lemma
inv_of_mul_self_assoc
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_mul_self", "invertible", "monoid", "one_mul" ]
null
82
84
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_inv_of_self_assoc [monoid α] (a b : α) [invertible a] : a * (⅟a * b) = b := by rw [←mul_assoc, mul_inv_of_self, one_mul]
mul_inv_of_self_assoc [monoid α] (a b : α) [invertible a] : a * (⅟a * b) = b
by rw [←mul_assoc, mul_inv_of_self, one_mul]
lemma
mul_inv_of_self_assoc
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "monoid", "mul_inv_of_self", "one_mul" ]
null
86
88
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_inv_of_mul_self_cancel [monoid α] (a b : α) [invertible b] : a * ⅟b * b = a := by simp [mul_assoc]
mul_inv_of_mul_self_cancel [monoid α] (a b : α) [invertible b] : a * ⅟b * b = a
by simp [mul_assoc]
lemma
mul_inv_of_mul_self_cancel
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "monoid", "mul_assoc" ]
null
90
92
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_mul_inv_of_self_cancel [monoid α] (a b : α) [invertible b] : a * b * ⅟b = a := by simp [mul_assoc]
mul_mul_inv_of_self_cancel [monoid α] (a b : α) [invertible b] : a * b * ⅟b = a
by simp [mul_assoc]
lemma
mul_mul_inv_of_self_cancel
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "monoid", "mul_assoc" ]
null
94
96
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_eq_right_inv [monoid α] {a b : α} [invertible a] (hac : a * b = 1) : ⅟a = b := left_inv_eq_right_inv (inv_of_mul_self _) hac
inv_of_eq_right_inv [monoid α] {a b : α} [invertible a] (hac : a * b = 1) : ⅟a = b
left_inv_eq_right_inv (inv_of_mul_self _) hac
lemma
inv_of_eq_right_inv
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_mul_self", "invertible", "left_inv_eq_right_inv", "monoid" ]
null
98
99
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_eq_left_inv [monoid α] {a b : α} [invertible a] (hac : b * a = 1) : ⅟a = b := (left_inv_eq_right_inv hac (mul_inv_of_self _)).symm
inv_of_eq_left_inv [monoid α] {a b : α} [invertible a] (hac : b * a = 1) : ⅟a = b
(left_inv_eq_right_inv hac (mul_inv_of_self _)).symm
lemma
inv_of_eq_left_inv
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "left_inv_eq_right_inv", "monoid", "mul_inv_of_self" ]
null
101
102
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_unique {α : Type u} [monoid α] (a b : α) [invertible a] [invertible b] (h : a = b) : ⅟a = ⅟b := by { apply inv_of_eq_right_inv, rw [h, mul_inv_of_self], }
invertible_unique {α : Type u} [monoid α] (a b : α) [invertible a] [invertible b] (h : a = b) : ⅟a = ⅟b
by { apply inv_of_eq_right_inv, rw [h, mul_inv_of_self], }
lemma
invertible_unique
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_eq_right_inv", "invertible", "monoid", "mul_inv_of_self" ]
null
104
107
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
[monoid α] (a : α) : subsingleton (invertible a) := ⟨ λ ⟨b, hba, hab⟩ ⟨c, hca, hac⟩, by { congr, exact left_inv_eq_right_inv hba hac } ⟩
[monoid α] (a : α) : subsingleton (invertible a)
⟨ λ ⟨b, hba, hab⟩ ⟨c, hca, hac⟩, by { congr, exact left_inv_eq_right_inv hba hac } ⟩
instance
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "left_inv_eq_right_inv", "monoid" ]
null
109
110
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible.copy' [mul_one_class α] {r : α} (hr : invertible r) (s : α) (si : α) (hs : s = r) (hsi : si = ⅟r) : invertible s := { inv_of := si, inv_of_mul_self := by rw [hs, hsi, inv_of_mul_self], mul_inv_of_self := by rw [hs, hsi, mul_inv_of_self] }
invertible.copy' [mul_one_class α] {r : α} (hr : invertible r) (s : α) (si : α) (hs : s = r) (hsi : si = ⅟r) : invertible s
{ inv_of := si, inv_of_mul_self := by rw [hs, hsi, inv_of_mul_self], mul_inv_of_self := by rw [hs, hsi, mul_inv_of_self] }
def
invertible.copy'
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_mul_self", "invertible", "mul_inv_of_self", "mul_one_class" ]
If `r` is invertible and `s = r` and `si = ⅟r`, then `s` is invertible with `⅟s = si`.
113
118
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible.copy [mul_one_class α] {r : α} (hr : invertible r) (s : α) (hs : s = r) : invertible s := hr.copy' _ _ hs rfl
invertible.copy [mul_one_class α] {r : α} (hr : invertible r) (s : α) (hs : s = r) : invertible s
hr.copy' _ _ hs rfl
def
invertible.copy
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "mul_one_class" ]
If `r` is invertible and `s = r`, then `s` is invertible.
121
124
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unit_of_invertible [monoid α] (a : α) [invertible a] : αˣ := { val := a, inv := ⅟a, val_inv := by simp, inv_val := by simp, }
unit_of_invertible [monoid α] (a : α) [invertible a] : αˣ
{ val := a, inv := ⅟a, val_inv := by simp, inv_val := by simp, }
def
unit_of_invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "monoid" ]
An `invertible` element is a unit.
127
132
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_unit_of_invertible [monoid α] (a : α) [invertible a] : is_unit a := ⟨unit_of_invertible a, rfl⟩
is_unit_of_invertible [monoid α] (a : α) [invertible a] : is_unit a
⟨unit_of_invertible a, rfl⟩
lemma
is_unit_of_invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "is_unit", "monoid" ]
null
134
135
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
units.invertible [monoid α] (u : αˣ) : invertible (u : α) := { inv_of := ↑(u⁻¹), inv_of_mul_self := u.inv_mul, mul_inv_of_self := u.mul_inv }
units.invertible [monoid α] (u : αˣ) : invertible (u : α)
{ inv_of := ↑(u⁻¹), inv_of_mul_self := u.inv_mul, mul_inv_of_self := u.mul_inv }
def
units.invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_mul_self", "invertible", "monoid", "mul_inv_of_self" ]
Units are invertible in their associated monoid.
138
139
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_units [monoid α] (u : αˣ) [invertible (u : α)] : ⅟(u : α) = ↑(u⁻¹) := inv_of_eq_right_inv u.mul_inv
inv_of_units [monoid α] (u : αˣ) [invertible (u : α)] : ⅟(u : α) = ↑(u⁻¹)
inv_of_eq_right_inv u.mul_inv
lemma
inv_of_units
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_eq_right_inv", "invertible", "monoid" ]
null
141
142
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_unit.nonempty_invertible [monoid α] {a : α} (h : is_unit a) : nonempty (invertible a) := let ⟨x, hx⟩ := h in ⟨x.invertible.copy _ hx.symm⟩
is_unit.nonempty_invertible [monoid α] {a : α} (h : is_unit a) : nonempty (invertible a)
let ⟨x, hx⟩ := h in ⟨x.invertible.copy _ hx.symm⟩
lemma
is_unit.nonempty_invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "is_unit", "monoid" ]
null
144
145
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_unit.invertible [monoid α] {a : α} (h : is_unit a) : invertible a := classical.choice h.nonempty_invertible
is_unit.invertible [monoid α] {a : α} (h : is_unit a) : invertible a
classical.choice h.nonempty_invertible
def
is_unit.invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "is_unit", "monoid" ]
Convert `is_unit` to `invertible` using `classical.choice`. Prefer `casesI h.nonempty_invertible` over `letI := h.invertible` if you want to avoid choice.
150
151
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonempty_invertible_iff_is_unit [monoid α] (a : α) : nonempty (invertible a) ↔ is_unit a := ⟨nonempty.rec $ @is_unit_of_invertible _ _ _, is_unit.nonempty_invertible⟩
nonempty_invertible_iff_is_unit [monoid α] (a : α) : nonempty (invertible a) ↔ is_unit a
⟨nonempty.rec $ @is_unit_of_invertible _ _ _, is_unit.nonempty_invertible⟩
lemma
nonempty_invertible_iff_is_unit
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "is_unit", "is_unit_of_invertible", "monoid" ]
null
153
155
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_of_group [group α] (a : α) : invertible a := ⟨a⁻¹, inv_mul_self a, mul_inv_self a⟩
invertible_of_group [group α] (a : α) : invertible a
⟨a⁻¹, inv_mul_self a, mul_inv_self a⟩
def
invertible_of_group
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "group", "inv_mul_self", "invertible", "mul_inv_self" ]
Each element of a group is invertible.
158
159
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_eq_group_inv [group α] (a : α) [invertible a] : ⅟a = a⁻¹ := inv_of_eq_right_inv (mul_inv_self a)
inv_of_eq_group_inv [group α] (a : α) [invertible a] : ⅟a = a⁻¹
inv_of_eq_right_inv (mul_inv_self a)
lemma
inv_of_eq_group_inv
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "group", "inv_of_eq_right_inv", "invertible", "mul_inv_self" ]
null
161
162
true
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83