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infPrime_ofDual {a : αᵒᵈ} : InfPrime (ofDual a) ↔ SupPrime a := Iff.rfl alias ⟨_, InfIrred.dual⟩ := supIrred_toDual alias ⟨_, InfPrime.dual⟩ := supPrime_toDual alias ⟨_, SupIrred.ofDual⟩ := infIrred_ofDual alias ⟨_, SupPrime.ofDual⟩ := infPrime_ofDual
theorem
Order
[ "Mathlib.Data.Finset.Lattice.Fold" ]
Mathlib/Order/Irreducible.lean
infPrime_ofDual
null
@[simp] supPrime_iff_supIrred : SupPrime a ↔ SupIrred a := ⟨SupPrime.supIrred, And.imp_right fun h b c => by simp_rw [← inf_eq_left, inf_sup_left]; exact @h _ _⟩ @[simp]
theorem
Order
[ "Mathlib.Data.Finset.Lattice.Fold" ]
Mathlib/Order/Irreducible.lean
supPrime_iff_supIrred
null
infPrime_iff_infIrred : InfPrime a ↔ InfIrred a := ⟨InfPrime.infIrred, And.imp_right fun h b c => by simp_rw [← sup_eq_left, sup_inf_left]; exact @h _ _⟩ protected alias ⟨_, SupIrred.supPrime⟩ := supPrime_iff_supIrred protected alias ⟨_, InfIrred.infPrime⟩ := infPrime_iff_infIrred
theorem
Order
[ "Mathlib.Data.Finset.Lattice.Fold" ]
Mathlib/Order/Irreducible.lean
infPrime_iff_infIrred
null
supPrime_iff_not_isMin : SupPrime a ↔ ¬IsMin a := and_iff_left <| by simp
theorem
Order
[ "Mathlib.Data.Finset.Lattice.Fold" ]
Mathlib/Order/Irreducible.lean
supPrime_iff_not_isMin
null
infPrime_iff_not_isMax : InfPrime a ↔ ¬IsMax a := and_iff_left <| by simp @[simp]
theorem
Order
[ "Mathlib.Data.Finset.Lattice.Fold" ]
Mathlib/Order/Irreducible.lean
infPrime_iff_not_isMax
null
supIrred_iff_not_isMin : SupIrred a ↔ ¬IsMin a := and_iff_left fun _ _ => by simpa only [max_eq_iff] using Or.imp And.left And.left @[simp]
theorem
Order
[ "Mathlib.Data.Finset.Lattice.Fold" ]
Mathlib/Order/Irreducible.lean
supIrred_iff_not_isMin
null
infIrred_iff_not_isMax : InfIrred a ↔ ¬IsMax a := and_iff_left fun _ _ => by simpa only [min_eq_iff] using Or.imp And.left And.left
theorem
Order
[ "Mathlib.Data.Finset.Lattice.Fold" ]
Mathlib/Order/Irreducible.lean
infIrred_iff_not_isMax
null
@[mk_iff isNormal_iff'] IsNormal [LinearOrder α] [LinearOrder β] (f : α → β) : Prop where strictMono : StrictMono f /-- This condition is the RHS of the `IsLUB (f '' Iio a) (f a)` predicate, which is sufficient since the LHS is implied by monotonicity. -/ mem_lowerBounds_upperBounds_of_isSuccLimit {a : α} (ha :...
structure
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
IsNormal
A normal function between well-orders is a strictly monotonic continuous function.
isNormal_iff [LinearOrder α] [LinearOrder β] {f : α → β} : IsNormal f ↔ StrictMono f ∧ ∀ o, IsSuccLimit o → ∀ a, (∀ b < o, f b ≤ a) → f o ≤ a := by simp [isNormal_iff', mem_lowerBounds, mem_upperBounds]
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
isNormal_iff
null
isLUB_image_Iio_of_isSuccLimit {f : α → β} (hf : IsNormal f) {a : α} (ha : IsSuccLimit a) : IsLUB (f '' Iio a) (f a) := by refine ⟨?_, hf.2 ha⟩ rintro - ⟨b, hb, rfl⟩ exact (hf.1 hb).le @[deprecated "use the default constructor of `IsNormal` directly" (since := "2025-07-08")]
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
isLUB_image_Iio_of_isSuccLimit
null
of_mem_lowerBounds_upperBounds {f : α → β} (hf : StrictMono f) (hl : ∀ {a}, IsSuccLimit a → f a ∈ lowerBounds (upperBounds (f '' Iio a))) : IsNormal f := ⟨hf, hl⟩
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
of_mem_lowerBounds_upperBounds
null
le_iff_forall_le (hf : IsNormal f) (ha : IsSuccLimit a) {b : β} : f a ≤ b ↔ ∀ a' < a, f a' ≤ b := by simpa [mem_upperBounds] using isLUB_le_iff (hf.isLUB_image_Iio_of_isSuccLimit ha)
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
le_iff_forall_le
null
lt_iff_exists_lt (hf : IsNormal f) (ha : IsSuccLimit a) {b : β} : b < f a ↔ ∃ a' < a, b < f a' := by simpa [mem_upperBounds] using lt_isLUB_iff (hf.isLUB_image_Iio_of_isSuccLimit ha)
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
lt_iff_exists_lt
null
map_isSuccLimit (hf : IsNormal f) (ha : IsSuccLimit a) : IsSuccLimit (f a) := by refine ⟨?_, fun b hb ↦ ?_⟩ · obtain ⟨b, hb⟩ := not_isMin_iff.1 ha.not_isMin exact not_isMin_iff.2 ⟨_, hf.strictMono hb⟩ · obtain ⟨c, hc, hc'⟩ := (hf.lt_iff_exists_lt ha).1 hb.lt have hc' := hb.ge_of_gt hc' rw [hf.strictMo...
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
map_isSuccLimit
null
map_isLUB (hf : IsNormal f) {s : Set α} (hs : IsLUB s a) (hs' : s.Nonempty) : IsLUB (f '' s) (f a) := by refine ⟨?_, fun b hb ↦ ?_⟩ · simpa [mem_upperBounds, hf.strictMono.le_iff_le] using hs.1 · by_cases ha : a ∈ s · simp_all [mem_upperBounds] · have ha' := hs.isSuccLimit_of_notMem hs' ha rw [l...
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
map_isLUB
null
_root_.InitialSeg.isNormal (f : α ≤i β) : IsNormal f where strictMono := f.strictMono mem_lowerBounds_upperBounds_of_isSuccLimit ha := by rw [f.image_Iio] exact (f.map_isSuccLimit ha).isLUB_Iio.2
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
_root_.InitialSeg.isNormal
null
_root_.PrincipalSeg.isNormal (f : α <i β) : IsNormal f := (f : α ≤i β).isNormal
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
_root_.PrincipalSeg.isNormal
null
_root_.OrderIso.isNormal (f : α ≃o β) : IsNormal f := f.toInitialSeg.isNormal
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
_root_.OrderIso.isNormal
null
protected id : IsNormal (@id α) := (OrderIso.refl _).isNormal
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
id
null
comp (hg : IsNormal g) (hf : IsNormal f) : IsNormal (g ∘ f) := by refine ⟨hg.strictMono.comp hf.strictMono, fun ha b hb ↦ ?_⟩ simp_rw [Function.comp_apply, mem_upperBounds, forall_mem_image] at hb simpa [hg.le_iff_forall_le (hf.map_isSuccLimit ha), hf.lt_iff_exists_lt ha] using fun c d hd hc ↦ (hg.strictMono ...
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
comp
null
of_succ_lt (hs : ∀ a, f a < f (succ a)) (hl : ∀ {a}, IsSuccLimit a → IsLUB (f '' Iio a) (f a)) : IsNormal f := by refine ⟨fun a b ↦ ?_, fun ha ↦ (hl ha).2⟩ induction b using SuccOrder.limitRecOn with | isMin b hb => exact hb.not_lt.elim | succ b hb IH => intro hab obtain rfl | h := (lt_succ_iff_...
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
of_succ_lt
null
protected ext [OrderBot α] {g : α → β} (hf : IsNormal f) (hg : IsNormal g) : f = g ↔ f ⊥ = g ⊥ ∧ ∀ a, f a = g a → f (succ a) = g (succ a) := by constructor · simp_all rintro ⟨H₁, H₂⟩ ext a induction a using SuccOrder.limitRecOn with | isMin a ha => rw [ha.eq_bot, H₁] | succ a ha IH => exact H₂ a IH ...
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
ext
null
map_sSup (hf : IsNormal f) {s : Set α} (hs : s.Nonempty) (hs' : BddAbove s) : f (sSup s) = sSup (f '' s) := ((hf.map_isLUB (isLUB_csSup hs hs') hs).csSup_eq (hs.image f)).symm
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
map_sSup
null
map_iSup {ι} [Nonempty ι] {g : ι → α} (hf : IsNormal f) (hg : BddAbove (range g)) : f (⨆ i, g i) = ⨆ i, f (g i) := by unfold iSup convert map_sSup hf (range_nonempty g) hg ext simp
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
map_iSup
null
preimage_Iic (hf : IsNormal f) {x : β} (h₁ : (f ⁻¹' Iic x).Nonempty) (h₂ : BddAbove (f ⁻¹' Iic x)) : f ⁻¹' Iic x = Iic (sSup (f ⁻¹' Iic x)) := by refine le_antisymm (fun _ ↦ le_csSup h₂) (fun y hy ↦ ?_) obtain hy | rfl := hy.lt_or_eq · rw [lt_csSup_iff h₂ h₁] at hy obtain ⟨z, hz, hyz⟩ := hy exact ...
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
preimage_Iic
null
apply_of_isSuccLimit (hf : IsNormal f) (ha : IsSuccLimit a) : f a = ⨆ b : Iio a, f b := by convert map_iSup hf _ · exact ha.iSup_Iio.symm · exact ⟨⊥, ha.bot_lt⟩ · use a rintro _ ⟨⟨x, hx⟩, rfl⟩ exact hx.le
theorem
Order
[ "Mathlib.Order.SuccPred.CompleteLinearOrder", "Mathlib.Order.SuccPred.InitialSeg" ]
Mathlib/Order/IsNormal.lean
apply_of_isSuccLimit
null
seq_le_seq (hf : Monotone f) (n : ℕ) (h₀ : x 0 ≤ y 0) (hx : ∀ k < n, x (k + 1) ≤ f (x k)) (hy : ∀ k < n, f (y k) ≤ y (k + 1)) : x n ≤ y n := by induction n with | zero => exact h₀ | succ n ihn => refine (hx _ n.lt_succ_self).trans ((hf <| ihn ?_ ?_).trans (hy _ n.lt_succ_self)) · exact fun k hk => hx ...
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
seq_le_seq
null
seq_pos_lt_seq_of_lt_of_le (hf : Monotone f) {n : ℕ} (hn : 0 < n) (h₀ : x 0 ≤ y 0) (hx : ∀ k < n, x (k + 1) < f (x k)) (hy : ∀ k < n, f (y k) ≤ y (k + 1)) : x n < y n := by induction n with | zero => exact hn.false.elim | succ n ihn => suffices x n ≤ y n from (hx n n.lt_succ_self).trans_le ((hf this).trans ...
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
seq_pos_lt_seq_of_lt_of_le
null
seq_pos_lt_seq_of_le_of_lt (hf : Monotone f) {n : ℕ} (hn : 0 < n) (h₀ : x 0 ≤ y 0) (hx : ∀ k < n, x (k + 1) ≤ f (x k)) (hy : ∀ k < n, f (y k) < y (k + 1)) : x n < y n := hf.dual.seq_pos_lt_seq_of_lt_of_le hn h₀ hy hx
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
seq_pos_lt_seq_of_le_of_lt
null
seq_lt_seq_of_lt_of_le (hf : Monotone f) (n : ℕ) (h₀ : x 0 < y 0) (hx : ∀ k < n, x (k + 1) < f (x k)) (hy : ∀ k < n, f (y k) ≤ y (k + 1)) : x n < y n := by cases n exacts [h₀, hf.seq_pos_lt_seq_of_lt_of_le (Nat.zero_lt_succ _) h₀.le hx hy]
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
seq_lt_seq_of_lt_of_le
null
seq_lt_seq_of_le_of_lt (hf : Monotone f) (n : ℕ) (h₀ : x 0 < y 0) (hx : ∀ k < n, x (k + 1) ≤ f (x k)) (hy : ∀ k < n, f (y k) < y (k + 1)) : x n < y n := hf.dual.seq_lt_seq_of_lt_of_le n h₀ hy hx /-!
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
seq_lt_seq_of_le_of_lt
null
le_iterate_comp_of_le (hf : Monotone f) (H : h ∘ g ≤ f ∘ h) (n : ℕ) : h ∘ g^[n] ≤ f^[n] ∘ h := fun x => by apply hf.seq_le_seq n <;> intros <;> simp [iterate_succ', -iterate_succ, comp_apply, id_eq, le_refl] case hx => exact H _
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
le_iterate_comp_of_le
null
iterate_comp_le_of_le (hf : Monotone f) (H : f ∘ h ≤ h ∘ g) (n : ℕ) : f^[n] ∘ h ≤ h ∘ g^[n] := hf.dual.le_iterate_comp_of_le H n
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
iterate_comp_le_of_le
null
iterate_le_of_le {g : α → α} (hf : Monotone f) (h : f ≤ g) (n : ℕ) : f^[n] ≤ g^[n] := hf.iterate_comp_le_of_le h n
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
iterate_le_of_le
If `f ≤ g` and `f` is monotone, then `f^[n] ≤ g^[n]`.
le_iterate_of_le {g : α → α} (hg : Monotone g) (h : f ≤ g) (n : ℕ) : f^[n] ≤ g^[n] := hg.dual.iterate_le_of_le h n
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
le_iterate_of_le
If `f ≤ g` and `g` is monotone, then `f^[n] ≤ g^[n]`.
id_le_iterate_of_id_le (h : id ≤ f) (n : ℕ) : id ≤ f^[n] := by simpa only [iterate_id] using monotone_id.iterate_le_of_le h n
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
id_le_iterate_of_id_le
If $x ≤ f x$ for all $x$ (we write this as `id ≤ f`), then the same is true for any iterate `f^[n]` of `f`.
iterate_le_id_of_le_id (h : f ≤ id) (n : ℕ) : f^[n] ≤ id := @id_le_iterate_of_id_le αᵒᵈ _ f h n
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
iterate_le_id_of_le_id
null
monotone_iterate_of_id_le (h : id ≤ f) : Monotone fun m => f^[m] := monotone_nat_of_le_succ fun n x => by rw [iterate_succ_apply'] exact h _
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
monotone_iterate_of_id_le
null
antitone_iterate_of_le_id (h : f ≤ id) : Antitone fun m => f^[m] := fun m n hmn => @monotone_iterate_of_id_le αᵒᵈ _ f h m n hmn
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
antitone_iterate_of_le_id
null
iterate_le_of_map_le (h : Commute f g) (hf : Monotone f) (hg : Monotone g) {x} (hx : f x ≤ g x) (n : ℕ) : f^[n] x ≤ g^[n] x := by apply hf.seq_le_seq n · rfl · intros; rw [iterate_succ_apply'] · simp [h.iterate_right _ _, hg.iterate _ hx]
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
iterate_le_of_map_le
null
iterate_pos_lt_of_map_lt (h : Commute f g) (hf : Monotone f) (hg : StrictMono g) {x} (hx : f x < g x) {n} (hn : 0 < n) : f^[n] x < g^[n] x := by apply hf.seq_pos_lt_seq_of_le_of_lt hn · rfl · intros; rw [iterate_succ_apply'] · simp [h.iterate_right _ _, hg.iterate _ hx]
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
iterate_pos_lt_of_map_lt
null
iterate_pos_lt_of_map_lt' (h : Commute f g) (hf : StrictMono f) (hg : Monotone g) {x} (hx : f x < g x) {n} (hn : 0 < n) : f^[n] x < g^[n] x := @iterate_pos_lt_of_map_lt αᵒᵈ _ g f h.symm hg.dual hf.dual x hx n hn
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
iterate_pos_lt_of_map_lt'
null
iterate_pos_lt_iff_map_lt (h : Commute f g) (hf : Monotone f) (hg : StrictMono g) {x n} (hn : 0 < n) : f^[n] x < g^[n] x ↔ f x < g x := by rcases lt_trichotomy (f x) (g x) with (H | H | H) · simp only [*, iterate_pos_lt_of_map_lt] · simp only [*, h.iterate_eq_of_map_eq, lt_irrefl] · simp only [lt_asymm H, l...
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
iterate_pos_lt_iff_map_lt
null
iterate_pos_lt_iff_map_lt' (h : Commute f g) (hf : StrictMono f) (hg : Monotone g) {x n} (hn : 0 < n) : f^[n] x < g^[n] x ↔ f x < g x := @iterate_pos_lt_iff_map_lt αᵒᵈ _ _ _ h.symm hg.dual hf.dual x n hn
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
iterate_pos_lt_iff_map_lt'
null
iterate_pos_le_iff_map_le (h : Commute f g) (hf : Monotone f) (hg : StrictMono g) {x n} (hn : 0 < n) : f^[n] x ≤ g^[n] x ↔ f x ≤ g x := by simpa only [not_lt] using not_congr (h.symm.iterate_pos_lt_iff_map_lt' hg hf hn)
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
iterate_pos_le_iff_map_le
null
iterate_pos_le_iff_map_le' (h : Commute f g) (hf : StrictMono f) (hg : Monotone g) {x n} (hn : 0 < n) : f^[n] x ≤ g^[n] x ↔ f x ≤ g x := by simpa only [not_lt] using not_congr (h.symm.iterate_pos_lt_iff_map_lt hg hf hn)
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
iterate_pos_le_iff_map_le'
null
iterate_pos_eq_iff_map_eq (h : Commute f g) (hf : Monotone f) (hg : StrictMono g) {x n} (hn : 0 < n) : f^[n] x = g^[n] x ↔ f x = g x := by simp only [le_antisymm_iff, h.iterate_pos_le_iff_map_le hf hg hn, h.symm.iterate_pos_le_iff_map_le' hg hf hn]
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
iterate_pos_eq_iff_map_eq
null
monotone_iterate_of_le_map (hf : Monotone f) (hx : x ≤ f x) : Monotone fun n => f^[n] x := monotone_nat_of_le_succ fun n => by rw [iterate_succ_apply] exact hf.iterate n hx
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
monotone_iterate_of_le_map
If `f` is a monotone map and `x ≤ f x` at some point `x`, then the iterates `f^[n] x` form a monotone sequence.
antitone_iterate_of_map_le (hf : Monotone f) (hx : f x ≤ x) : Antitone fun n => f^[n] x := hf.dual.monotone_iterate_of_le_map hx
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
antitone_iterate_of_map_le
If `f` is a monotone map and `f x ≤ x` at some point `x`, then the iterates `f^[n] x` form an antitone sequence.
strictMono_iterate_of_lt_map (hf : StrictMono f) (hx : x < f x) : StrictMono fun n => f^[n] x := strictMono_nat_of_lt_succ fun n => by rw [iterate_succ_apply] exact hf.iterate n hx
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
strictMono_iterate_of_lt_map
If `f` is a strictly monotone map and `x < f x` at some point `x`, then the iterates `f^[n] x` form a strictly monotone sequence.
strictAnti_iterate_of_map_lt (hf : StrictMono f) (hx : f x < x) : StrictAnti fun n => f^[n] x := hf.dual.strictMono_iterate_of_lt_map hx
theorem
Order
[ "Mathlib.Logic.Function.Iterate", "Mathlib.Order.Monotone.Basic" ]
Mathlib/Order/Iterate.lean
strictAnti_iterate_of_map_lt
If `f` is a strictly antitone map and `f x < x` at some point `x`, then the iterates `f^[n] x` form a strictly antitone sequence.
JordanHolderLattice (X : Type u) [Lattice X] where IsMaximal : X → X → Prop lt_of_isMaximal : ∀ {x y}, IsMaximal x y → x < y sup_eq_of_isMaximal : ∀ {x y z}, IsMaximal x z → IsMaximal y z → x ≠ y → x ⊔ y = z isMaximal_inf_left_of_isMaximal_sup : ∀ {x y}, IsMaximal x (x ⊔ y) → IsMaximal y (x ⊔ y) → IsMaximal...
class
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
JordanHolderLattice
A `JordanHolderLattice` is the class for which the Jordan Hölder theorem is proved. A Jordan Hölder lattice is a lattice equipped with a notion of maximality, `IsMaximal`, and a notion of isomorphism of pairs `Iso`. In the example of subgroups of a group, `IsMaximal H K` means that `H` is a maximal normal subgroup of `...
isMaximal_inf_right_of_isMaximal_sup {x y : X} (hxz : IsMaximal x (x ⊔ y)) (hyz : IsMaximal y (x ⊔ y)) : IsMaximal (x ⊓ y) y := by rw [inf_comm] rw [sup_comm] at hxz hyz exact isMaximal_inf_left_of_isMaximal_sup hyz hxz
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
isMaximal_inf_right_of_isMaximal_sup
null
isMaximal_of_eq_inf (x b : X) {a y : X} (ha : x ⊓ y = a) (hxy : x ≠ y) (hxb : IsMaximal x b) (hyb : IsMaximal y b) : IsMaximal a y := by have hb : x ⊔ y = b := sup_eq_of_isMaximal hxb hyb hxy substs a b exact isMaximal_inf_right_of_isMaximal_sup hxb hyb
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
isMaximal_of_eq_inf
null
second_iso_of_eq {x y a b : X} (hm : IsMaximal x a) (ha : x ⊔ y = a) (hb : x ⊓ y = b) : Iso (x, a) (b, y) := by substs a b; exact second_iso hm
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
second_iso_of_eq
null
IsMaximal.iso_refl {x y : X} (h : IsMaximal x y) : Iso (x, y) (x, y) := second_iso_of_eq h (sup_eq_right.2 (le_of_lt (lt_of_isMaximal h))) (inf_eq_left.2 (le_of_lt (lt_of_isMaximal h)))
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
IsMaximal.iso_refl
null
CompositionSeries (X : Type u) [Lattice X] [JordanHolderLattice X] : Type u := RelSeries {(x, y) : X × X | IsMaximal x y}
abbrev
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
CompositionSeries
A `CompositionSeries X` is a finite nonempty series of elements of a `JordanHolderLattice` such that each element is maximal inside the next. The length of a `CompositionSeries X` is one less than the number of elements in the series. Note that there is no stipulation that a series start from the bottom of the lattice ...
lt_succ (s : CompositionSeries X) (i : Fin s.length) : s (Fin.castSucc i) < s (Fin.succ i) := lt_of_isMaximal (s.step _)
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
lt_succ
null
protected strictMono (s : CompositionSeries X) : StrictMono s := Fin.strictMono_iff_lt_succ.2 s.lt_succ
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
strictMono
null
protected injective (s : CompositionSeries X) : Function.Injective s := s.strictMono.injective @[simp]
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
injective
null
protected inj (s : CompositionSeries X) {i j : Fin s.length.succ} : s i = s j ↔ i = j := s.injective.eq_iff
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
inj
null
total {s : CompositionSeries X} {x y : X} (hx : x ∈ s) (hy : y ∈ s) : x ≤ y ∨ y ≤ x := by rcases Set.mem_range.1 hx with ⟨i, rfl⟩ rcases Set.mem_range.1 hy with ⟨j, rfl⟩ rw [s.strictMono.le_iff_le, s.strictMono.le_iff_le] exact le_total i j
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
total
null
toList_sorted (s : CompositionSeries X) : s.toList.Sorted (· < ·) := List.pairwise_iff_get.2 fun i j h => by dsimp only [RelSeries.toList] rw [List.get_ofFn, List.get_ofFn] exact s.strictMono h
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
toList_sorted
null
toList_nodup (s : CompositionSeries X) : s.toList.Nodup := s.toList_sorted.nodup
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
toList_nodup
null
@[ext] ext {s₁ s₂ : CompositionSeries X} (h : ∀ x, x ∈ s₁ ↔ x ∈ s₂) : s₁ = s₂ := toList_injective <| List.eq_of_perm_of_sorted (by classical exact List.perm_of_nodup_nodup_toFinset_eq s₁.toList_nodup s₂.toList_nodup (Finset.ext <| by simpa only [List.mem_toFinset, RelSeries.mem_toL...
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
ext
Two `CompositionSeries` are equal if they have the same elements. See also `ext_fun`.
le_last {s : CompositionSeries X} (i : Fin (s.length + 1)) : s i ≤ s.last := s.strictMono.monotone (Fin.le_last _)
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
le_last
null
le_last_of_mem {s : CompositionSeries X} {x : X} (hx : x ∈ s) : x ≤ s.last := let ⟨_i, hi⟩ := Set.mem_range.2 hx hi ▸ le_last _ @[simp]
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
le_last_of_mem
null
head_le {s : CompositionSeries X} (i : Fin (s.length + 1)) : s.head ≤ s i := s.strictMono.monotone (Fin.zero_le _)
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
head_le
null
head_le_of_mem {s : CompositionSeries X} {x : X} (hx : x ∈ s) : s.head ≤ x := let ⟨_i, hi⟩ := Set.mem_range.2 hx hi ▸ head_le _
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
head_le_of_mem
null
last_eraseLast_le (s : CompositionSeries X) : s.eraseLast.last ≤ s.last := by simp [eraseLast, last, s.strictMono.le_iff_le, Fin.le_iff_val_le_val]
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
last_eraseLast_le
null
mem_eraseLast_of_ne_of_mem {s : CompositionSeries X} {x : X} (hx : x ≠ s.last) (hxs : x ∈ s) : x ∈ s.eraseLast := by rcases hxs with ⟨i, rfl⟩ have hi : (i : ℕ) < (s.length - 1).succ := by conv_rhs => rw [← Nat.succ_sub (length_pos_of_nontrivial ⟨_, ⟨i, rfl⟩, _, s.last_mem, hx⟩), Nat.add_one_sub_one] ...
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
mem_eraseLast_of_ne_of_mem
null
mem_eraseLast {s : CompositionSeries X} {x : X} (h : 0 < s.length) : x ∈ s.eraseLast ↔ x ≠ s.last ∧ x ∈ s := by simp only [RelSeries.mem_def, eraseLast] constructor · rintro ⟨i, rfl⟩ have hi : (i : ℕ) < s.length := by omega simp [last, Fin.ext_iff, ne_of_lt hi, -Set.mem_range, Set.mem_range_self] · ...
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
mem_eraseLast
null
lt_last_of_mem_eraseLast {s : CompositionSeries X} {x : X} (h : 0 < s.length) (hx : x ∈ s.eraseLast) : x < s.last := lt_of_le_of_ne (le_last_of_mem ((mem_eraseLast h).1 hx).2) ((mem_eraseLast h).1 hx).1
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
lt_last_of_mem_eraseLast
null
isMaximal_eraseLast_last {s : CompositionSeries X} (h : 0 < s.length) : IsMaximal s.eraseLast.last s.last := by rw [last_eraseLast, last] have := s.step ⟨s.length - 1, by cutsat⟩ simp only [Fin.castSucc_mk, Fin.succ_mk, mem_setOf_eq] at this convert this using 3 exact (tsub_add_cancel_of_le h).symm
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
isMaximal_eraseLast_last
null
eq_snoc_eraseLast {s : CompositionSeries X} (h : 0 < s.length) : s = snoc (eraseLast s) s.last (isMaximal_eraseLast_last h) := by ext x simp only [mem_snoc, mem_eraseLast h, ne_eq] by_cases h : x = s.last <;> simp [*, s.last_mem] @[simp]
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
eq_snoc_eraseLast
null
snoc_eraseLast_last {s : CompositionSeries X} (h : IsMaximal s.eraseLast.last s.last) : s.eraseLast.snoc s.last h = s := have h : 0 < s.length := Nat.pos_of_ne_zero (fun hs => ne_of_gt (lt_of_isMaximal h) <| by simp [last, Fin.ext_iff, hs]) (eq_snoc_eraseLast h).symm
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
snoc_eraseLast_last
null
Equivalent (s₁ s₂ : CompositionSeries X) : Prop := ∃ f : Fin s₁.length ≃ Fin s₂.length, ∀ i : Fin s₁.length, Iso (s₁ (Fin.castSucc i), s₁ i.succ) (s₂ (Fin.castSucc (f i)), s₂ (Fin.succ (f i)))
def
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
Equivalent
Two `CompositionSeries X`, `s₁` and `s₂` are equivalent if there is a bijection `e : Fin s₁.length ≃ Fin s₂.length` such that for any `i`, `Iso (s₁ i) (s₁ i.succ) (s₂ (e i), s₂ (e i.succ))`
@[refl] refl (s : CompositionSeries X) : Equivalent s s := ⟨Equiv.refl _, fun _ => (s.step _).iso_refl⟩ @[symm]
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
refl
null
symm {s₁ s₂ : CompositionSeries X} (h : Equivalent s₁ s₂) : Equivalent s₂ s₁ := ⟨h.choose.symm, fun i => iso_symm (by simpa using h.choose_spec (h.choose.symm i))⟩ @[trans]
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
symm
null
trans {s₁ s₂ s₃ : CompositionSeries X} (h₁ : Equivalent s₁ s₂) (h₂ : Equivalent s₂ s₃) : Equivalent s₁ s₃ := ⟨h₁.choose.trans h₂.choose, fun i => iso_trans (h₁.choose_spec i) (h₂.choose_spec (h₁.choose i))⟩
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
trans
null
protected smash {s₁ s₂ t₁ t₂ : CompositionSeries X} (hs : s₁.last = s₂.head) (ht : t₁.last = t₂.head) (h₁ : Equivalent s₁ t₁) (h₂ : Equivalent s₂ t₂) : Equivalent (smash s₁ s₂ hs) (smash t₁ t₂ ht) := let e : Fin (s₁.length + s₂.length) ≃ Fin (t₁.length + t₂.length) := calc Fin (s₁.length + s₂.le...
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
smash
null
protected snoc {s₁ s₂ : CompositionSeries X} {x₁ x₂ : X} {hsat₁ : IsMaximal s₁.last x₁} {hsat₂ : IsMaximal s₂.last x₂} (hequiv : Equivalent s₁ s₂) (hlast : Iso (s₁.last, x₁) (s₂.last, x₂)) : Equivalent (s₁.snoc x₁ hsat₁) (s₂.snoc x₂ hsat₂) := let e : Fin s₁.length.succ ≃ Fin s₂.length.succ := calc F...
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
snoc
null
length_eq {s₁ s₂ : CompositionSeries X} (h : Equivalent s₁ s₂) : s₁.length = s₂.length := by simpa using Fintype.card_congr h.choose
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
length_eq
null
snoc_snoc_swap {s : CompositionSeries X} {x₁ x₂ y₁ y₂ : X} {hsat₁ : IsMaximal s.last x₁} {hsat₂ : IsMaximal s.last x₂} {hsaty₁ : IsMaximal (snoc s x₁ hsat₁).last y₁} {hsaty₂ : IsMaximal (snoc s x₂ hsat₂).last y₂} (hr₁ : Iso (s.last, x₁) (x₂, y₂)) (hr₂ : Iso (x₁, y₁) (s.last, x₂)) : Equivalent (snoc (sno...
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
snoc_snoc_swap
null
length_eq_zero_of_head_eq_head_of_last_eq_last_of_length_eq_zero {s₁ s₂ : CompositionSeries X} (hb : s₁.head = s₂.head) (ht : s₁.last = s₂.last) (hs₁ : s₁.length = 0) : s₂.length = 0 := by have : Fin.last s₂.length = (0 : Fin s₂.length.succ) := s₂.injective (hb.symm.trans ((congr_arg s₁ (Fin.ext (by simp ...
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
length_eq_zero_of_head_eq_head_of_last_eq_last_of_length_eq_zero
null
length_pos_of_head_eq_head_of_last_eq_last_of_length_pos {s₁ s₂ : CompositionSeries X} (hb : s₁.head = s₂.head) (ht : s₁.last = s₂.last) : 0 < s₁.length → 0 < s₂.length := not_imp_not.1 (by simpa only [pos_iff_ne_zero, ne_eq, Decidable.not_not] using length_eq_zero_of_head_eq_head_of_last_eq_las...
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
length_pos_of_head_eq_head_of_last_eq_last_of_length_pos
null
eq_of_head_eq_head_of_last_eq_last_of_length_eq_zero {s₁ s₂ : CompositionSeries X} (hb : s₁.head = s₂.head) (ht : s₁.last = s₂.last) (hs₁0 : s₁.length = 0) : s₁ = s₂ := by have : ∀ x, x ∈ s₁ ↔ x = s₁.last := fun x => ⟨fun hx => subsingleton_of_length_eq_zero hs₁0 hx s₁.last_mem, fun hx => hx.symm ▸ s₁.last_m...
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
eq_of_head_eq_head_of_last_eq_last_of_length_eq_zero
null
exists_last_eq_snoc_equivalent (s : CompositionSeries X) (x : X) (hm : IsMaximal x s.last) (hb : s.head ≤ x) : ∃ t : CompositionSeries X, t.head = s.head ∧ t.length + 1 = s.length ∧ ∃ htx : t.last = x, Equivalent s (snoc t s.last (show IsMaximal t.last _ from htx.symm ▸ hm)) := by inductio...
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
exists_last_eq_snoc_equivalent
Given a `CompositionSeries`, `s`, and an element `x` such that `x` is maximal inside `s.last` there is a series, `t`, such that `t.last = x`, `t.head = s.head` and `snoc t s.last _` is equivalent to `s`.
jordan_holder (s₁ s₂ : CompositionSeries X) (hb : s₁.head = s₂.head) (ht : s₁.last = s₂.last) : Equivalent s₁ s₂ := by induction hle : s₁.length generalizing s₁ s₂ with | zero => rw [eq_of_head_eq_head_of_last_eq_last_of_length_eq_zero hb ht hle] | succ n ih => have h0s₂ : 0 < s₂.length := lengt...
theorem
Order
[ "Mathlib.Order.Lattice", "Mathlib.Data.List.Sort", "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Logic.Equiv.Functor", "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.RelSeries" ]
Mathlib/Order/JordanHolder.lean
jordan_holder
The **Jordan-Hölder** theorem, stated for any `JordanHolderLattice`. If two composition series start and finish at the same place, they are equivalent.
exists_seq_covby_of_forall_covby_finite (hfin : ∀ (a : α), {x | a ⋖ x}.Finite) (hb : (Ici b).Infinite) : ∃ f : ℕ → α, f 0 = b ∧ ∀ i, f i ⋖ f (i+1) := let h := fun a : {a : α // (Ici a).Infinite} ↦ exists_covby_infinite_Ici_of_infinite_Ici a.2 (hfin a) let ks : ℕ → {a : α // (Ici a).Infinite} := Nat.rec ⟨b, ...
theorem
Order
[ "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.Atoms.Finite", "Mathlib.Order.Grade", "Mathlib.Tactic.ApplyFun" ]
Mathlib/Order/KonigLemma.lean
exists_seq_covby_of_forall_covby_finite
**Kőnig's infinity lemma** : if each element in a strongly atomic order is covered by only finitely many others, and `b` is an element with infinitely many things above it, then there is a sequence starting with `b` in which each element is covered by the next.
exists_orderEmbedding_covby_of_forall_covby_finite (hfin : ∀ (a : α), {x | a ⋖ x}.Finite) (hb : (Ici b).Infinite) : ∃ f : ℕ ↪o α, f 0 = b ∧ ∀ i, f i ⋖ f (i+1) := by obtain ⟨f, hf⟩ := exists_seq_covby_of_forall_covby_finite hfin hb exact ⟨OrderEmbedding.ofStrictMono f (strictMono_nat_of_lt_succ (fun i ↦ (hf.2 i)...
theorem
Order
[ "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.Atoms.Finite", "Mathlib.Order.Grade", "Mathlib.Tactic.ApplyFun" ]
Mathlib/Order/KonigLemma.lean
exists_orderEmbedding_covby_of_forall_covby_finite
The sequence given by Kőnig's lemma as an order embedding
exists_orderEmbedding_covby_of_forall_covby_finite_of_bot [OrderBot α] [Infinite α] (hfin : ∀ (a : α), {x | a ⋖ x}.Finite) : ∃ f : ℕ ↪o α, f 0 = ⊥ ∧ ∀ i, f i ⋖ f (i+1) := exists_orderEmbedding_covby_of_forall_covby_finite hfin (by simpa using infinite_univ)
theorem
Order
[ "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.Atoms.Finite", "Mathlib.Order.Grade", "Mathlib.Tactic.ApplyFun" ]
Mathlib/Order/KonigLemma.lean
exists_orderEmbedding_covby_of_forall_covby_finite_of_bot
A version of Kőnig's lemma where the sequence starts at the minimum of an infinite order.
GradeMinOrder.exists_nat_orderEmbedding_of_forall_covby_finite [GradeMinOrder ℕ α] [OrderBot α] [Infinite α] (hfin : ∀ (a : α), {x | a ⋖ x}.Finite) : ∃ f : ℕ ↪o α, f 0 = ⊥ ∧ (∀ i, f i ⋖ f (i+1)) ∧ ∀ i, grade ℕ (f i) = i := by obtain ⟨f, h0, hf⟩ := exists_orderEmbedding_covby_of_forall_covby_finite_of_bot hfin...
theorem
Order
[ "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.Atoms.Finite", "Mathlib.Order.Grade", "Mathlib.Tactic.ApplyFun" ]
Mathlib/Order/KonigLemma.lean
GradeMinOrder.exists_nat_orderEmbedding_of_forall_covby_finite
null
exists_seq_forall_proj_of_forall_finite {α : ℕ → Type*} [Finite (α 0)] [∀ i, Nonempty (α i)] (π : {i j : ℕ} → (hij : i ≤ j) → α j → α i) (π_refl : ∀ ⦃i⦄ (a : α i), π rfl.le a = a) (π_trans : ∀ ⦃i j k⦄ (hij : i ≤ j) (hjk : j ≤ k) a, π hij (π hjk a) = π (hij.trans hjk) a) (hfin : ∀ i a, {b : α (i+1) | π (...
theorem
Order
[ "Mathlib.Data.Fintype.Pigeonhole", "Mathlib.Order.Atoms.Finite", "Mathlib.Order.Grade", "Mathlib.Tactic.ApplyFun" ]
Mathlib/Order/KonigLemma.lean
exists_seq_forall_proj_of_forall_finite
A formulation of Kőnig's infinity lemma, useful in applications. Given a sequence `α 0, α 1, ...` of nonempty types with `α 0` finite, and a well-behaved family of projections `π : α j → α i` for all `i ≤ j`, if each term in each `α i` is the projection of only finitely many terms in `α (i+1)`, then we can find a seque...
noncomputable krullDim (α : Type*) [Preorder α] : WithBot ℕ∞ := ⨆ (p : LTSeries α), p.length
def
Order
[ "Mathlib.Algebra.Order.Group.Int", "Mathlib.Algebra.Order.SuccPred.WithBot", "Mathlib.Data.ENat.Lattice", "Mathlib.Order.Atoms", "Mathlib.Order.RelSeries", "Mathlib.Tactic.FinCases" ]
Mathlib/Order/KrullDimension.lean
krullDim
The **Krull dimension** of a preorder `α` is the supremum of the rightmost index of all relation series of `α` ordered by `<`. If there is no series `a₀ < a₁ < ... < aₙ` in `α`, then its Krull dimension is defined to be negative infinity; if the length of all series `a₀ < a₁ < ... < aₙ` is unbounded, its Krull dimensio...
noncomputable height {α : Type*} [Preorder α] (a : α) : ℕ∞ := ⨆ (p : LTSeries α) (_ : p.last ≤ a), p.length
def
Order
[ "Mathlib.Algebra.Order.Group.Int", "Mathlib.Algebra.Order.SuccPred.WithBot", "Mathlib.Data.ENat.Lattice", "Mathlib.Order.Atoms", "Mathlib.Order.RelSeries", "Mathlib.Tactic.FinCases" ]
Mathlib/Order/KrullDimension.lean
height
The **height** of an element `a` in a preorder `α` is the supremum of the rightmost index of all relation series of `α` ordered by `<` and ending below or at `a`. In other words, it is the largest `n` such that there's a series `a₀ < a₁ < ... < aₙ = a` (or `∞` if there is no largest `n`).
noncomputable coheight {α : Type*} [Preorder α] (a : α) : ℕ∞ := height (α := αᵒᵈ) a
def
Order
[ "Mathlib.Algebra.Order.Group.Int", "Mathlib.Algebra.Order.SuccPred.WithBot", "Mathlib.Data.ENat.Lattice", "Mathlib.Order.Atoms", "Mathlib.Order.RelSeries", "Mathlib.Tactic.FinCases" ]
Mathlib/Order/KrullDimension.lean
coheight
The **coheight** of an element `a` in a preorder `α` is the supremum of the rightmost index of all relation series of `α` ordered by `<` and beginning with `a`. In other words, it is the largest `n` such that there's a series `a = a₀ < a₁ < ... < aₙ` (or `∞` if there is no largest `n`). The definition of `coheight` is...
@[simp] height_toDual (x : α) : height (OrderDual.toDual x) = coheight x := rfl @[simp] lemma height_ofDual (x : αᵒᵈ) : height (OrderDual.ofDual x) = coheight x := rfl @[simp] lemma coheight_toDual (x : α) : coheight (OrderDual.toDual x) = height x := rfl @[simp] lemma coheight_ofDual (x : αᵒᵈ) : coheight (OrderDual.of...
lemma
Order
[ "Mathlib.Algebra.Order.Group.Int", "Mathlib.Algebra.Order.SuccPred.WithBot", "Mathlib.Data.ENat.Lattice", "Mathlib.Order.Atoms", "Mathlib.Order.RelSeries", "Mathlib.Tactic.FinCases" ]
Mathlib/Order/KrullDimension.lean
height_toDual
null
coheight_eq (a : α) : coheight a = ⨆ (p : LTSeries α) (_ : a ≤ p.head), (p.length : ℕ∞) := by apply Equiv.iSup_congr ⟨RelSeries.reverse, RelSeries.reverse, fun _ ↦ RelSeries.reverse_reverse _, fun _ ↦ RelSeries.reverse_reverse _⟩ congr! 1
lemma
Order
[ "Mathlib.Algebra.Order.Group.Int", "Mathlib.Algebra.Order.SuccPred.WithBot", "Mathlib.Data.ENat.Lattice", "Mathlib.Order.Atoms", "Mathlib.Order.RelSeries", "Mathlib.Tactic.FinCases" ]
Mathlib/Order/KrullDimension.lean
coheight_eq
The **coheight** of an element `a` in a preorder `α` is the supremum of the rightmost index of all relation series of `α` ordered by `<` and beginning with `a`. This is not the definition of `coheight`. The definition of `coheight` is via the `height` in the dual order, in order to easily transfer theorems between `he...
height_le_iff {a : α} {n : ℕ∞} : height a ≤ n ↔ ∀ ⦃p : LTSeries α⦄, p.last ≤ a → p.length ≤ n := by rw [height, iSup₂_le_iff]
lemma
Order
[ "Mathlib.Algebra.Order.Group.Int", "Mathlib.Algebra.Order.SuccPred.WithBot", "Mathlib.Data.ENat.Lattice", "Mathlib.Order.Atoms", "Mathlib.Order.RelSeries", "Mathlib.Tactic.FinCases" ]
Mathlib/Order/KrullDimension.lean
height_le_iff
null