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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" ]
[]
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)
lemma
set.mul_indicator_apply_le_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "le_rfl" ]
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)
lemma
set.mul_indicator_le_one
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
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)
lemma
set.mul_indicator_le_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "le_rfl" ]
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 _))
lemma
set.mul_indicator_le_mul_indicator_of_subset
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "le_rfl" ]
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
lemma
set.mul_indicator_le_self'
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "le_rfl" ]
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 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" ]
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 _
lemma
set.mul_indicator_le_self
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "one_le" ]
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 _
lemma
set.mul_indicator_apply_le
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "one_le" ]
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 _
lemma
set.mul_indicator_le
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "one_le" ]
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
lemma
set.indicator_le_indicator_nonneg
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "le_rfl" ]
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
lemma
set.indicator_nonpos_le_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[]
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
lemma
monoid_hom.map_mul_indicator
algebra
src/algebra/indicator_function.lean
[ "algebra.support" ]
[ "mul_one_class", "set.mul_indicator_comp_of_one" ]
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)
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`.
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
lemma
inv_of_mul_self
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible" ]
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
lemma
mul_inv_of_self
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible" ]
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]
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" ]
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]
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" ]
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]
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" ]
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]
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" ]
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
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" ]
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
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" ]
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], }
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" ]
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] }
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`.
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
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.
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, }
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.
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⟩
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" ]
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 }
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.
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
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" ]
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⟩
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" ]
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
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.
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⟩
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" ]
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⟩
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.
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)
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" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_one [monoid α] : invertible (1 : α)
⟨1, mul_one _, one_mul _⟩
def
invertible_one
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "monoid", "mul_one", "one_mul" ]
`1` is the inverse of itself
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_one [monoid α] [invertible (1 : α)] : ⅟(1 : α) = 1
inv_of_eq_right_inv (mul_one _)
lemma
inv_of_one
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_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_neg [has_mul α] [has_one α] [has_distrib_neg α] (a : α) [invertible a] : invertible (-a)
⟨-⅟a, by simp, by simp ⟩
def
invertible_neg
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "has_distrib_neg", "invertible" ]
`-⅟a` is the inverse of `-a`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_neg [monoid α] [has_distrib_neg α] (a : α) [invertible a] [invertible (-a)] : ⅟(-a) = -⅟a
inv_of_eq_right_inv (by simp)
lemma
inv_of_neg
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "has_distrib_neg", "inv_of_eq_right_inv", "invertible", "monoid" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_sub_inv_of_two [ring α] [invertible (2:α)] : 1 - (⅟2:α) = ⅟2
(is_unit_of_invertible (2:α)).mul_right_inj.1 $ by rw [mul_sub, mul_inv_of_self, mul_one, bit0, add_sub_cancel]
lemma
one_sub_inv_of_two
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "is_unit_of_invertible", "mul_inv_of_self", "mul_one", "ring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_two_add_inv_of_two [non_assoc_semiring α] [invertible (2 : α)] : (⅟2 : α) + (⅟2 : α) = 1
by rw [←two_mul, mul_inv_of_self]
lemma
inv_of_two_add_inv_of_two
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "mul_inv_of_self", "non_assoc_semiring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_inv_of [has_one α] [has_mul α] {a : α} [invertible a] : invertible (⅟a)
⟨ a, mul_inv_of_self a, inv_of_mul_self a ⟩
instance
invertible_inv_of
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" ]
`a` is the inverse of `⅟a`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_inv_of [monoid α] (a : α) [invertible a] [invertible (⅟a)] : ⅟(⅟a) = a
inv_of_eq_right_inv (inv_of_mul_self _)
lemma
inv_of_inv_of
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_eq_right_inv", "inv_of_mul_self", "invertible", "monoid" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_inj [monoid α] {a b : α} [invertible a] [invertible b] : ⅟ a = ⅟ b ↔ a = b
⟨invertible_unique _ _, invertible_unique _ _⟩
lemma
inv_of_inj
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "invertible_unique", "monoid" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_mul [monoid α] (a b : α) [invertible a] [invertible b] : invertible (a * b)
⟨ ⅟b * ⅟a, by simp [←mul_assoc], by simp [←mul_assoc] ⟩
def
invertible_mul
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "monoid" ]
`⅟b * ⅟a` is the inverse of `a * b`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_mul [monoid α] (a b : α) [invertible a] [invertible b] [invertible (a * b)] : ⅟(a * b) = ⅟b * ⅟a
inv_of_eq_right_inv (by simp [←mul_assoc])
lemma
inv_of_mul
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_eq_right_inv", "invertible", "monoid" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible.mul [monoid α] {a b : α} (ha : invertible a) (hb : invertible b) : invertible (a * b)
invertible_mul _ _
def
invertible.mul
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "invertible_mul", "monoid" ]
A copy of `invertible_mul` for dot notation.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
commute.inv_of_right [monoid α] {a b : α} [invertible b] (h : commute a b) : commute a (⅟b)
calc a * (⅟b) = (⅟b) * (b * a * (⅟b)) : by simp [mul_assoc] ... = (⅟b) * (a * b * ((⅟b))) : by rw h.eq ... = (⅟b) * a : by simp [mul_assoc]
theorem
commute.inv_of_right
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "commute", "invertible", "monoid", "mul_assoc" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
commute.inv_of_left [monoid α] {a b : α} [invertible b] (h : commute b a) : commute (⅟b) a
calc (⅟b) * a = (⅟b) * (a * b * (⅟b)) : by simp [mul_assoc] ... = (⅟b) * (b * a * (⅟b)) : by rw h.eq ... = a * (⅟b) : by simp [mul_assoc]
theorem
commute.inv_of_left
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "commute", "invertible", "monoid", "mul_assoc" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
commute_inv_of {M : Type*} [has_one M] [has_mul M] (m : M) [invertible m] : commute m (⅟m)
calc m * ⅟m = 1 : mul_inv_of_self m ... = ⅟ m * m : (inv_of_mul_self m).symm
lemma
commute_inv_of
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "commute", "inv_of_mul_self", "invertible", "mul_inv_of_self" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonzero_of_invertible [mul_zero_one_class α] (a : α) [nontrivial α] [invertible a] : a ≠ 0
λ ha, zero_ne_one $ calc 0 = ⅟a * a : by simp [ha] ... = 1 : inv_of_mul_self a
lemma
nonzero_of_invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_mul_self", "invertible", "mul_zero_one_class", "nontrivial", "zero_ne_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible.ne_zero [mul_zero_one_class α] [nontrivial α] (a : α) [invertible a] : ne_zero a
⟨nonzero_of_invertible a⟩
instance
invertible.ne_zero
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "mul_zero_one_class", "ne_zero", "nontrivial" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_of_invertible_mul (a b : α) [invertible a] [invertible (a * b)] : invertible b
{ inv_of := ⅟(a * b) * a, inv_of_mul_self := by rw [mul_assoc, inv_of_mul_self], mul_inv_of_self := by rw [←(is_unit_of_invertible a).mul_right_inj, ←mul_assoc, ←mul_assoc, mul_inv_of_self, mul_one, one_mul] }
def
invertible_of_invertible_mul
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_mul_self", "invertible", "is_unit_of_invertible", "mul_assoc", "mul_inv_of_self", "mul_one", "mul_right_inj", "one_mul" ]
This is the `invertible` version of `units.is_unit_units_mul`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_of_mul_invertible (a b : α) [invertible (a * b)] [invertible b] : invertible a
{ inv_of := b * ⅟(a * b), inv_of_mul_self := by rw [←(is_unit_of_invertible b).mul_left_inj, mul_assoc, mul_assoc, inv_of_mul_self, mul_one, one_mul], mul_inv_of_self := by rw [←mul_assoc, mul_inv_of_self] }
def
invertible_of_mul_invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_mul_self", "invertible", "is_unit_of_invertible", "mul_assoc", "mul_inv_of_self", "mul_left_inj", "mul_one", "one_mul" ]
This is the `invertible` version of `units.is_unit_mul_units`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible.mul_left {a : α} (ha : invertible a) (b : α) : invertible b ≃ invertible (a * b)
{ to_fun := λ hb, by exactI invertible_mul a b, inv_fun := λ hab, by exactI invertible_of_invertible_mul a _, left_inv := λ hb, subsingleton.elim _ _, right_inv := λ hab, subsingleton.elim _ _, }
def
invertible.mul_left
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_fun", "invertible", "invertible_mul", "invertible_of_invertible_mul" ]
`invertible_of_invertible_mul` and `invertible_mul` as an equivalence.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible.mul_right (a : α) {b : α} (ha : invertible b) : invertible a ≃ invertible (a * b)
{ to_fun := λ hb, by exactI invertible_mul a b, inv_fun := λ hab, by exactI invertible_of_mul_invertible _ b, left_inv := λ hb, subsingleton.elim _ _, right_inv := λ hab, subsingleton.elim _ _, }
def
invertible.mul_right
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_fun", "invertible", "invertible_mul", "invertible_of_mul_invertible" ]
`invertible_of_mul_invertible` and `invertible_mul` as an equivalence.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ring.inverse_invertible (x : α) [invertible x] : ring.inverse x = ⅟x
ring.inverse_unit (unit_of_invertible _)
lemma
ring.inverse_invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "ring.inverse", "ring.inverse_unit", "unit_of_invertible" ]
A variant of `ring.inverse_unit`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_of_nonzero {a : α} (h : a ≠ 0) : invertible a
⟨ a⁻¹, inv_mul_cancel h, mul_inv_cancel h ⟩
def
invertible_of_nonzero
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_mul_cancel", "invertible", "mul_inv_cancel" ]
`a⁻¹` is an inverse of `a` if `a ≠ 0`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_eq_inv (a : α) [invertible a] : ⅟a = a⁻¹
inv_of_eq_right_inv (mul_inv_cancel (nonzero_of_invertible a))
lemma
inv_of_eq_inv
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_eq_right_inv", "invertible", "mul_inv_cancel", "nonzero_of_invertible" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_mul_cancel_of_invertible (a : α) [invertible a] : a⁻¹ * a = 1
inv_mul_cancel (nonzero_of_invertible a)
lemma
inv_mul_cancel_of_invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_mul_cancel", "invertible", "nonzero_of_invertible" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_inv_cancel_of_invertible (a : α) [invertible a] : a * a⁻¹ = 1
mul_inv_cancel (nonzero_of_invertible a)
lemma
mul_inv_cancel_of_invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "mul_inv_cancel", "nonzero_of_invertible" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_mul_cancel_of_invertible (a b : α) [invertible b] : a / b * b = a
div_mul_cancel a (nonzero_of_invertible b)
lemma
div_mul_cancel_of_invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "div_mul_cancel", "invertible", "nonzero_of_invertible" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_div_cancel_of_invertible (a b : α) [invertible b] : a * b / b = a
mul_div_cancel a (nonzero_of_invertible b)
lemma
mul_div_cancel_of_invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "mul_div_cancel", "nonzero_of_invertible" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_self_of_invertible (a : α) [invertible a] : a / a = 1
div_self (nonzero_of_invertible a)
lemma
div_self_of_invertible
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "div_self", "invertible", "nonzero_of_invertible" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_div (a b : α) [invertible a] [invertible b] : invertible (a / b)
⟨b / a, by simp [←mul_div_assoc], by simp [←mul_div_assoc]⟩
def
invertible_div
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible" ]
`b / a` is the inverse of `a / b`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_of_div (a b : α) [invertible a] [invertible b] [invertible (a / b)] : ⅟(a / b) = b / a
inv_of_eq_right_inv (by simp [←mul_div_assoc])
lemma
inv_of_div
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_eq_right_inv", "invertible" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_inv {a : α} [invertible a] : invertible (a⁻¹)
⟨ a, by simp, by simp ⟩
def
invertible_inv
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible" ]
`a` is the inverse of `a⁻¹`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible.map {R : Type*} {S : Type*} {F : Type*} [mul_one_class R] [mul_one_class S] [monoid_hom_class F R S] (f : F) (r : R) [invertible r] : invertible (f r)
{ inv_of := f (⅟r), inv_of_mul_self := by rw [←map_mul, inv_of_mul_self, map_one], mul_inv_of_self := by rw [←map_mul, mul_inv_of_self, map_one] }
def
invertible.map
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_of_mul_self", "invertible", "map_one", "monoid_hom_class", "mul_inv_of_self", "mul_one_class" ]
Monoid homs preserve invertibility.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_inv_of {R : Type*} {S : Type*} {F : Type*} [mul_one_class R] [monoid S] [monoid_hom_class F R S] (f : F) (r : R) [invertible r] [invertible (f r)] : f (⅟r) = ⅟(f r)
by { letI := invertible.map f r, convert rfl }
lemma
map_inv_of
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "invertible.map", "monoid", "monoid_hom_class", "mul_one_class" ]
Note that the `invertible (f r)` argument can be satisfied by using `letI := invertible.map f r` before applying this lemma.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible.of_left_inverse {R : Type*} {S : Type*} {G : Type*} [mul_one_class R] [mul_one_class S] [monoid_hom_class G S R] (f : R → S) (g : G) (r : R) (h : function.left_inverse g f) [invertible (f r)] : invertible r
(invertible.map g (f r)).copy _ (h r).symm
def
invertible.of_left_inverse
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "invertible", "invertible.map", "monoid_hom_class", "mul_one_class" ]
If a function `f : R → S` has a left-inverse that is a monoid hom, then `r : R` is invertible if `f r` is. The inverse is computed as `g (⅟(f r))`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
invertible_equiv_of_left_inverse {R : Type*} {S : Type*} {F G : Type*} [monoid R] [monoid S] [monoid_hom_class F R S] [monoid_hom_class G S R] (f : F) (g : G) (r : R) (h : function.left_inverse g f) : invertible (f r) ≃ invertible r
{ to_fun := λ _, by exactI invertible.of_left_inverse f _ _ h, inv_fun := λ _, by exactI invertible.map f _, left_inv := λ x, subsingleton.elim _ _, right_inv := λ x, subsingleton.elim _ _ }
def
invertible_equiv_of_left_inverse
algebra
src/algebra/invertible.lean
[ "algebra.group.units", "algebra.group_with_zero.units.lemmas", "algebra.ring.defs" ]
[ "inv_fun", "invertible", "invertible.map", "invertible.of_left_inverse", "monoid", "monoid_hom_class" ]
Invertibility on either side of a monoid hom with a left-inverse is equivalent.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow : Prop
∃ (p : R) (k : ℕ), prime p ∧ 0 < k ∧ p ^ k = n
def
is_prime_pow
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "prime" ]
`n` is a prime power if there is a prime `p` and a positive natural `k` such that `n` can be written as `p^k`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow_def : is_prime_pow n ↔ ∃ (p : R) (k : ℕ), prime p ∧ 0 < k ∧ p ^ k = n
iff.rfl
lemma
is_prime_pow_def
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "prime" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow_iff_pow_succ : is_prime_pow n ↔ ∃ (p : R) (k : ℕ), prime p ∧ p ^ (k + 1) = n
(is_prime_pow_def _).trans ⟨λ ⟨p, k, hp, hk, hn⟩, ⟨_, _, hp, by rwa [nat.sub_add_cancel hk]⟩, λ ⟨p, k, hp, hn⟩, ⟨_, _, hp, nat.succ_pos', hn⟩⟩
lemma
is_prime_pow_iff_pow_succ
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "is_prime_pow_def", "nat.succ_pos'", "prime" ]
An equivalent definition for prime powers: `n` is a prime power iff there is a prime `p` and a natural `k` such that `n` can be written as `p^(k+1)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
not_is_prime_pow_zero [no_zero_divisors R] : ¬ is_prime_pow (0 : R)
begin simp only [is_prime_pow_def, not_exists, not_and', and_imp], intros x n hn hx, rw pow_eq_zero hx, simp, end
lemma
not_is_prime_pow_zero
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "and_imp", "is_prime_pow", "is_prime_pow_def", "no_zero_divisors", "not_and'", "not_exists", "pow_eq_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow.not_unit {n : R} (h : is_prime_pow n) : ¬is_unit n
let ⟨p, k, hp, hk, hn⟩ := h in hn ▸ (is_unit_pow_iff hk.ne').not.mpr hp.not_unit
lemma
is_prime_pow.not_unit
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "is_unit", "is_unit_pow_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_unit.not_is_prime_pow {n : R} (h : is_unit n) : ¬is_prime_pow n
λ h', h'.not_unit h
lemma
is_unit.not_is_prime_pow
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "is_unit" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
not_is_prime_pow_one : ¬ is_prime_pow (1 : R)
is_unit_one.not_is_prime_pow
lemma
not_is_prime_pow_one
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prime.is_prime_pow {p : R} (hp : prime p) : is_prime_pow p
⟨p, 1, hp, zero_lt_one, by simp⟩
lemma
prime.is_prime_pow
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "prime", "zero_lt_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow.pow {n : R} (hn : is_prime_pow n) {k : ℕ} (hk : k ≠ 0) : is_prime_pow (n ^ k)
let ⟨p, k', hp, hk', hn⟩ := hn in ⟨p, k * k', hp, mul_pos hk.bot_lt hk', by rw [pow_mul', hn]⟩
lemma
is_prime_pow.pow
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "pow_mul'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow.ne_zero [no_zero_divisors R] {n : R} (h : is_prime_pow n) : n ≠ 0
λ t, eq.rec not_is_prime_pow_zero t.symm h
theorem
is_prime_pow.ne_zero
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "no_zero_divisors", "not_is_prime_pow_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow.ne_one {n : R} (h : is_prime_pow n) : n ≠ 1
λ t, eq.rec not_is_prime_pow_one t.symm h
lemma
is_prime_pow.ne_one
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "not_is_prime_pow_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow_nat_iff (n : ℕ) : is_prime_pow n ↔ ∃ (p k : ℕ), nat.prime p ∧ 0 < k ∧ p ^ k = n
by simp only [is_prime_pow_def, nat.prime_iff]
lemma
is_prime_pow_nat_iff
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "is_prime_pow_def", "nat.prime", "nat.prime_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nat.prime.is_prime_pow {p : ℕ} (hp : p.prime) : is_prime_pow p
hp.prime.is_prime_pow
lemma
nat.prime.is_prime_pow
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow_nat_iff_bounded (n : ℕ) : is_prime_pow n ↔ ∃ (p : ℕ), p ≤ n ∧ ∃ (k : ℕ), k ≤ n ∧ p.prime ∧ 0 < k ∧ p ^ k = n
begin rw is_prime_pow_nat_iff, refine iff.symm ⟨λ ⟨p, _, k, _, hp, hk, hn⟩, ⟨p, k, hp, hk, hn⟩, _⟩, rintro ⟨p, k, hp, hk, rfl⟩, refine ⟨p, _, k, (nat.lt_pow_self hp.one_lt _).le, hp, hk, rfl⟩, simpa using nat.pow_le_pow_of_le_right hp.pos hk, end
lemma
is_prime_pow_nat_iff_bounded
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "is_prime_pow_nat_iff", "nat.lt_pow_self", "nat.pow_le_pow_of_le_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow.dvd {n m : ℕ} (hn : is_prime_pow n) (hm : m ∣ n) (hm₁ : m ≠ 1) : is_prime_pow m
begin rw is_prime_pow_nat_iff at hn ⊢, rcases hn with ⟨p, k, hp, hk, rfl⟩, obtain ⟨i, hik, rfl⟩ := (nat.dvd_prime_pow hp).1 hm, refine ⟨p, i, hp, _, rfl⟩, apply nat.pos_of_ne_zero, rintro rfl, simpa using hm₁, end
lemma
is_prime_pow.dvd
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "is_prime_pow_nat_iff", "nat.dvd_prime_pow" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nat.disjoint_divisors_filter_prime_pow {a b : ℕ} (hab : a.coprime b) : disjoint (a.divisors.filter is_prime_pow) (b.divisors.filter is_prime_pow)
begin simp only [finset.disjoint_left, finset.mem_filter, and_imp, nat.mem_divisors, not_and], rintro n han ha hn hbn hb -, exact hn.ne_one (nat.eq_one_of_dvd_coprimes hab han hbn), end
lemma
nat.disjoint_divisors_filter_prime_pow
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "and_imp", "disjoint", "finset.disjoint_left", "finset.mem_filter", "is_prime_pow", "nat.eq_one_of_dvd_coprimes", "nat.mem_divisors", "not_and" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow.two_le : ∀ {n : ℕ}, is_prime_pow n → 2 ≤ n
| 0 h := (not_is_prime_pow_zero h).elim | 1 h := (not_is_prime_pow_one h).elim | (n+2) _ := le_add_self
lemma
is_prime_pow.two_le
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "not_is_prime_pow_one", "not_is_prime_pow_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow.pos {n : ℕ} (hn : is_prime_pow n) : 0 < n
pos_of_gt hn.two_le
theorem
is_prime_pow.pos
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow", "pos_of_gt" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime_pow.one_lt {n : ℕ} (h : is_prime_pow n) : 1 < n
h.two_le
theorem
is_prime_pow.one_lt
algebra
src/algebra/is_prime_pow.lean
[ "algebra.associated", "number_theory.divisors" ]
[ "is_prime_pow" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_recurrence (α : Type*) [comm_semiring α]
(order : ℕ) (coeffs : fin order → α)
structure
linear_recurrence
algebra
src/algebra/linear_recurrence.lean
[ "data.polynomial.eval", "linear_algebra.dimension" ]
[ "comm_semiring" ]
A "linear recurrence relation" over a commutative semiring is given by its order `n` and `n` coefficients.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_solution (u : ℕ → α)
∀ n, u (n + E.order) = ∑ i, E.coeffs i * u (n + i)
def
linear_recurrence.is_solution
algebra
src/algebra/linear_recurrence.lean
[ "data.polynomial.eval", "linear_algebra.dimension" ]
[]
We say that a sequence `u` is solution of `linear_recurrence order coeffs` when we have `u (n + order) = ∑ i : fin order, coeffs i * u (n + i)` for any `n`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_sol (init : fin E.order → α) : ℕ → α
| n := if h : n < E.order then init ⟨n, h⟩ else ∑ k : fin E.order, have n - E.order + k < n := begin rw [add_comm, ← add_tsub_assoc_of_le (not_lt.mp h), tsub_lt_iff_left], { exact add_lt_add_right k.is_lt n }, { convert add_le_add (zero_le (k : ℕ)) (not_lt.mp h), simp only [zero_add]...
def
linear_recurrence.mk_sol
algebra
src/algebra/linear_recurrence.lean
[ "data.polynomial.eval", "linear_algebra.dimension" ]
[ "add_tsub_assoc_of_le", "tsub_lt_iff_left" ]
A solution of a `linear_recurrence` which satisfies certain initial conditions. We will prove this is the only such solution.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_sol_mk_sol (init : fin E.order → α) : E.is_solution (E.mk_sol init)
λ n, by rw mk_sol; simp
lemma
linear_recurrence.is_sol_mk_sol
algebra
src/algebra/linear_recurrence.lean
[ "data.polynomial.eval", "linear_algebra.dimension" ]
[]
`E.mk_sol` indeed gives solutions to `E`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_sol_eq_init (init : fin E.order → α) : ∀ n : fin E.order, E.mk_sol init n = init n
λ n, by { rw mk_sol, simp only [n.is_lt, dif_pos, fin.mk_coe, fin.eta] }
lemma
linear_recurrence.mk_sol_eq_init
algebra
src/algebra/linear_recurrence.lean
[ "data.polynomial.eval", "linear_algebra.dimension" ]
[ "fin.eta", "fin.mk_coe" ]
`E.mk_sol init`'s first `E.order` terms are `init`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_mk_of_is_sol_of_eq_init {u : ℕ → α} {init : fin E.order → α} (h : E.is_solution u) (heq : ∀ n : fin E.order, u n = init n) : ∀ n, u n = E.mk_sol init n
| n := if h' : n < E.order then by rw mk_sol; simp only [h', dif_pos]; exact_mod_cast heq ⟨n, h'⟩ else begin rw [mk_sol, ← tsub_add_cancel_of_le (le_of_not_lt h'), h (n-E.order)], simp [h'], congr' with k, exact have wf : n - E.order + k < n := begin rw [add_comm, ← add_tsub_assoc_of_l...
lemma
linear_recurrence.eq_mk_of_is_sol_of_eq_init
algebra
src/algebra/linear_recurrence.lean
[ "data.polynomial.eval", "linear_algebra.dimension" ]
[ "add_tsub_assoc_of_le", "tsub_add_cancel_of_le", "tsub_lt_iff_left" ]
If `u` is a solution to `E` and `init` designates its first `E.order` values, then `∀ n, u n = E.mk_sol init n`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_mk_of_is_sol_of_eq_init' {u : ℕ → α} {init : fin E.order → α} (h : E.is_solution u) (heq : ∀ n : fin E.order, u n = init n) : u = E.mk_sol init
funext (E.eq_mk_of_is_sol_of_eq_init h heq)
lemma
linear_recurrence.eq_mk_of_is_sol_of_eq_init'
algebra
src/algebra/linear_recurrence.lean
[ "data.polynomial.eval", "linear_algebra.dimension" ]
[]
If `u` is a solution to `E` and `init` designates its first `E.order` values, then `u = E.mk_sol init`. This proves that `E.mk_sol init` is the only solution of `E` whose first `E.order` values are given by `init`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sol_space : submodule α (ℕ → α)
{ carrier := {u | E.is_solution u}, zero_mem' := λ n, by simp, add_mem' := λ u v hu hv n, by simp [mul_add, sum_add_distrib, hu n, hv n], smul_mem' := λ a u hu n, by simp [hu n, mul_sum]; congr'; ext; ac_refl }
def
linear_recurrence.sol_space
algebra
src/algebra/linear_recurrence.lean
[ "data.polynomial.eval", "linear_algebra.dimension" ]
[ "submodule" ]
The space of solutions of `E`, as a `submodule` over `α` of the module `ℕ → α`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_sol_iff_mem_sol_space (u : ℕ → α) : E.is_solution u ↔ u ∈ E.sol_space
iff.rfl
lemma
linear_recurrence.is_sol_iff_mem_sol_space
algebra
src/algebra/linear_recurrence.lean
[ "data.polynomial.eval", "linear_algebra.dimension" ]
[]
Defining property of the solution space : `u` is a solution iff it belongs to the solution space.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_init : E.sol_space ≃ₗ[α] (fin E.order → α)
{ to_fun := λ u x, (u : ℕ → α) x, map_add' := λ u v, by { ext, simp }, map_smul' := λ a u, by { ext, simp }, inv_fun := λ u, ⟨E.mk_sol u, E.is_sol_mk_sol u⟩, left_inv := λ u, by ext n; symmetry; apply E.eq_mk_of_is_sol_of_eq_init u.2; intros k; refl, right_inv := λ u, function.funext_iff.mpr (λ n, E.mk_sol_eq...
def
linear_recurrence.to_init
algebra
src/algebra/linear_recurrence.lean
[ "data.polynomial.eval", "linear_algebra.dimension" ]
[ "inv_fun" ]
The function that maps a solution `u` of `E` to its first `E.order` terms as a `linear_equiv`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sol_eq_of_eq_init (u v : ℕ → α) (hu : E.is_solution u) (hv : E.is_solution v) : u = v ↔ set.eq_on u v ↑(range E.order)
begin refine iff.intro (λ h x hx, h ▸ rfl) _, intro h, set u' : ↥(E.sol_space) := ⟨u, hu⟩, set v' : ↥(E.sol_space) := ⟨v, hv⟩, change u'.val = v'.val, suffices h' : u' = v', from h' ▸ rfl, rw [← E.to_init.to_equiv.apply_eq_iff_eq, linear_equiv.coe_to_equiv], ext x, exact_mod_cast h (mem_range.mpr x.2)...
lemma
linear_recurrence.sol_eq_of_eq_init
algebra
src/algebra/linear_recurrence.lean
[ "data.polynomial.eval", "linear_algebra.dimension" ]
[ "linear_equiv.coe_to_equiv", "set.eq_on" ]
Two solutions are equal iff they are equal on `range E.order`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83