P. 333 of Theorem List - Metamath Proof Explorer

Theorem List for Metamath Proof Explorer - 33201-33300   *Has distinct variable group(s)

Type	Label	Description
Statement
Theorem	gsummptfsf1o 33201*	Re-index a finite group sum using a bijection. A version of gsummptf1o 19986 expressed using finite support. (Contributed by Thierry Arnoux, 5-Oct-2025.)
⊢ Ⅎ𝑥𝐻    &   ⊢ 𝐵 = (Base‘𝐺)    &   ⊢ 0 = (0g‘𝐺)    &   ⊢ (𝑥 = 𝐸 → 𝐶 = 𝐻)    &   ⊢ (𝜑 → 𝐺 ∈ CMnd)    &   ⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐶) finSupp 0 )    &   ⊢ (𝜑 → 𝐹 ⊆ 𝐵)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐶 ∈ 𝐹)    &   ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐷) → 𝐸 ∈ 𝐴)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ∃!𝑦 ∈ 𝐷 𝑥 = 𝐸)    ⇒   ⊢ (𝜑 → (𝐺 Σg (𝑥 ∈ 𝐴 ↦ 𝐶)) = (𝐺 Σg (𝑦 ∈ 𝐷 ↦ 𝐻)))
Theorem	gsumfs2d 33202*	Express a finite sum over a two-dimensional range as a double sum. Version of gsum2d 19995 using finite support. (Contributed by Thierry Arnoux, 5-Oct-2025.)
⊢ Ⅎ𝑥𝜑    &   ⊢ 𝐵 = (Base‘𝑊)    &   ⊢ 0 = (0g‘𝑊)    &   ⊢ (𝜑 → Rel 𝐴)    &   ⊢ (𝜑 → 𝐹 finSupp 0 )    &   ⊢ (𝜑 → 𝑊 ∈ CMnd)    &   ⊢ (𝜑 → 𝐹:𝐴⟶𝐵)    &   ⊢ (𝜑 → 𝐴 ∈ 𝑋)    ⇒   ⊢ (𝜑 → (𝑊 Σg 𝐹) = (𝑊 Σg (𝑥 ∈ dom 𝐴 ↦ (𝑊 Σg (𝑦 ∈ (𝐴 “ {𝑥}) ↦ (𝐹‘⟨𝑥, 𝑦⟩))))))
Theorem	gsumzresunsn 33203	Append an element to a finite group sum expressed as a function restriction. (Contributed by Thierry Arnoux, 20-Nov-2023.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ + = (+g‘𝐺)    &   ⊢ 𝑍 = (Cntz‘𝐺)    &   ⊢ 𝑌 = (𝐹‘𝑋)    &   ⊢ (𝜑 → 𝐹:𝐶⟶𝐵)    &   ⊢ (𝜑 → 𝐴 ⊆ 𝐶)    &   ⊢ (𝜑 → 𝐺 ∈ Mnd)    &   ⊢ (𝜑 → 𝐴 ∈ Fin)    &   ⊢ (𝜑 → ¬ 𝑋 ∈ 𝐴)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐶)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → (𝐹 “ (𝐴 ∪ {𝑋})) ⊆ (𝑍‘(𝐹 “ (𝐴 ∪ {𝑋}))))    ⇒   ⊢ (𝜑 → (𝐺 Σg (𝐹 ↾ (𝐴 ∪ {𝑋}))) = ((𝐺 Σg (𝐹 ↾ 𝐴)) + 𝑌))
Theorem	gsumpart 33204*	Express a group sum as a double sum, grouping along a (possibly infinite) partition. (Contributed by Thierry Arnoux, 22-Jun-2024.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ 0 = (0g‘𝐺)    &   ⊢ (𝜑 → 𝐺 ∈ CMnd)    &   ⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑊)    &   ⊢ (𝜑 → 𝐹:𝐴⟶𝐵)    &   ⊢ (𝜑 → 𝐹 finSupp 0 )    &   ⊢ (𝜑 → Disj 𝑥 ∈ 𝑋 𝐶)    &   ⊢ (𝜑 → ∪ 𝑥 ∈ 𝑋 𝐶 = 𝐴)    ⇒   ⊢ (𝜑 → (𝐺 Σg 𝐹) = (𝐺 Σg (𝑥 ∈ 𝑋 ↦ (𝐺 Σg (𝐹 ↾ 𝐶)))))
Theorem	gsumtp 33205*	Group sum of an unordered triple. (Contributed by Thierry Arnoux, 22-Jun-2025.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ + = (+g‘𝐺)    &   ⊢ (𝑘 = 𝑀 → 𝐴 = 𝐶)    &   ⊢ (𝑘 = 𝑁 → 𝐴 = 𝐷)    &   ⊢ (𝑘 = 𝑂 → 𝐴 = 𝐸)    &   ⊢ (𝜑 → 𝐺 ∈ CMnd)    &   ⊢ (𝜑 → 𝑀 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑁 ∈ 𝑊)    &   ⊢ (𝜑 → 𝑂 ∈ 𝑋)    &   ⊢ (𝜑 → 𝑀 ≠ 𝑁)    &   ⊢ (𝜑 → 𝑁 ≠ 𝑂)    &   ⊢ (𝜑 → 𝑀 ≠ 𝑂)    &   ⊢ (𝜑 → 𝐶 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐷 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐸 ∈ 𝐵)    ⇒   ⊢ (𝜑 → (𝐺 Σg (𝑘 ∈ {𝑀, 𝑁, 𝑂} ↦ 𝐴)) = ((𝐶 + 𝐷) + 𝐸))
Theorem	gsumzrsum 33206*	Relate a group sum on ℤring to a finite sum on the complex numbers. See also gsumfsum 21466. (Contributed by Thierry Arnoux, 5-Oct-2025.)
⊢ (𝜑 → 𝐴 ∈ Fin)    &   ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝐵 ∈ ℤ)    ⇒   ⊢ (𝜑 → (ℤring Σg (𝑘 ∈ 𝐴 ↦ 𝐵)) = Σ𝑘 ∈ 𝐴 𝐵)
Theorem	gsummulgc2 33207*	A finite group sum multiplied by a constant. (Contributed by Thierry Arnoux, 5-Oct-2025.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ · = (.g‘𝑀)    &   ⊢ (𝜑 → 𝑀 ∈ Grp)    &   ⊢ (𝜑 → 𝐴 ∈ Fin)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝑋 ∈ ℤ)    ⇒   ⊢ (𝜑 → (𝑀 Σg (𝑘 ∈ 𝐴 ↦ (𝑋 · 𝑌))) = (Σ𝑘 ∈ 𝐴 𝑋 · 𝑌))
Theorem	gsumhashmul 33208*	Express a group sum by grouping by nonzero values. (Contributed by Thierry Arnoux, 22-Jun-2024.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ 0 = (0g‘𝐺)    &   ⊢ · = (.g‘𝐺)    &   ⊢ (𝜑 → 𝐺 ∈ CMnd)    &   ⊢ (𝜑 → 𝐹:𝐴⟶𝐵)    &   ⊢ (𝜑 → 𝐹 finSupp 0 )    ⇒   ⊢ (𝜑 → (𝐺 Σg 𝐹) = (𝐺 Σg (𝑥 ∈ (ran 𝐹 ∖ { 0 }) ↦ ((♯‘(◡𝐹 “ {𝑥})) · 𝑥))))
Theorem	gsummulsubdishift1 33209*	Distribute a subtraction over an indexed sum, shift one of the resulting sums, and regroup terms. (Contributed by Thierry Arnoux, 15-Feb-2026.)
⊢ 𝐵 = (Base‘𝑅)    &   ⊢ + = (+g‘𝑅)    &   ⊢ − = (-g‘𝑅)    &   ⊢ · = (.r‘𝑅)    &   ⊢ (𝜑 → 𝑅 ∈ Ring)    &   ⊢ (𝜑 → 𝐴 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐶 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑁 ∈ ℕ0)    &   ⊢ (𝜑 → 𝐷:(0...𝑁)⟶𝐵)    &   ⊢ (𝜑 → 𝐸 = (((𝐷‘𝑁) · 𝐴) − ((𝐷‘0) · 𝐶)))    &   ⊢ ((𝜑 ∧ 𝑘 ∈ (0..^𝑁)) → 𝐹 = (((𝐷‘𝑘) · 𝐴) − ((𝐷‘(𝑘 + 1)) · 𝐶)))    ⇒   ⊢ (𝜑 → ((𝑅 Σg 𝐷) · (𝐴 − 𝐶)) = ((𝑅 Σg (𝑘 ∈ (0..^𝑁) ↦ 𝐹)) + 𝐸))
Theorem	gsummulsubdishift2 33210*	Distribute a subtraction over an indexed sum, shift one of the resulting sums, and regroup terms. (Contributed by Thierry Arnoux, 15-Feb-2026.)
⊢ 𝐵 = (Base‘𝑅)    &   ⊢ + = (+g‘𝑅)    &   ⊢ − = (-g‘𝑅)    &   ⊢ · = (.r‘𝑅)    &   ⊢ (𝜑 → 𝑅 ∈ Ring)    &   ⊢ (𝜑 → 𝐴 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐶 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑁 ∈ ℕ0)    &   ⊢ (𝜑 → 𝐷:(0...𝑁)⟶𝐵)    &   ⊢ (𝜑 → 𝐸 = (((𝐷‘0) · 𝐴) − ((𝐷‘𝑁) · 𝐶)))    &   ⊢ ((𝜑 ∧ 𝑘 ∈ (0..^𝑁)) → 𝐹 = (((𝐷‘(𝑘 + 1)) · 𝐴) − ((𝐷‘𝑘) · 𝐶)))    ⇒   ⊢ (𝜑 → ((𝑅 Σg 𝐷) · (𝐴 − 𝐶)) = ((𝑅 Σg (𝑘 ∈ (0..^𝑁) ↦ 𝐹)) + 𝐸))
Theorem	gsummulsubdishift1s 33211*	Distribute a subtraction over an indexed sum, shift one of the resulting sums, and regroup terms. (Contributed by Thierry Arnoux, 15-Feb-2026.)
⊢ 𝐵 = (Base‘𝑅)    &   ⊢ + = (+g‘𝑅)    &   ⊢ − = (-g‘𝑅)    &   ⊢ · = (.r‘𝑅)    &   ⊢ (𝜑 → 𝑅 ∈ Ring)    &   ⊢ (𝜑 → 𝐴 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐶 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑁 ∈ ℕ0)    &   ⊢ ((𝜑 ∧ 𝑖 ∈ (0...𝑁)) → 𝑉 ∈ 𝐵)    &   ⊢ (𝑖 = 0 → 𝑉 = 𝐺)    &   ⊢ (𝑖 = 𝑁 → 𝑉 = 𝐻)    &   ⊢ (𝑖 = 𝑘 → 𝑉 = 𝑃)    &   ⊢ (𝑖 = (𝑘 + 1) → 𝑉 = 𝑄)    &   ⊢ (𝜑 → 𝐸 = ((𝐻 · 𝐴) − (𝐺 · 𝐶)))    &   ⊢ ((𝜑 ∧ 𝑘 ∈ (0..^𝑁)) → 𝐹 = ((𝑃 · 𝐴) − (𝑄 · 𝐶)))    ⇒   ⊢ (𝜑 → ((𝑅 Σg (𝑘 ∈ (0...𝑁) ↦ 𝑃)) · (𝐴 − 𝐶)) = ((𝑅 Σg (𝑘 ∈ (0..^𝑁) ↦ 𝐹)) + 𝐸))
Theorem	gsummulsubdishift2s 33212*	Distribute a subtraction over an indexed sum, shift one of the resulting sums, and regroup terms. (Contributed by Thierry Arnoux, 15-Feb-2026.)
⊢ 𝐵 = (Base‘𝑅)    &   ⊢ + = (+g‘𝑅)    &   ⊢ − = (-g‘𝑅)    &   ⊢ · = (.r‘𝑅)    &   ⊢ (𝜑 → 𝑅 ∈ Ring)    &   ⊢ (𝜑 → 𝐴 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐶 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑁 ∈ ℕ0)    &   ⊢ ((𝜑 ∧ 𝑖 ∈ (0...𝑁)) → 𝑉 ∈ 𝐵)    &   ⊢ (𝑖 = 0 → 𝑉 = 𝐺)    &   ⊢ (𝑖 = 𝑁 → 𝑉 = 𝐻)    &   ⊢ (𝑖 = 𝑘 → 𝑉 = 𝑃)    &   ⊢ (𝑖 = (𝑘 + 1) → 𝑉 = 𝑄)    &   ⊢ (𝜑 → 𝐸 = ((𝐺 · 𝐴) − (𝐻 · 𝐶)))    &   ⊢ ((𝜑 ∧ 𝑘 ∈ (0..^𝑁)) → 𝐹 = ((𝑄 · 𝐴) − (𝑃 · 𝐶)))    ⇒   ⊢ (𝜑 → ((𝑅 Σg (𝑘 ∈ (0...𝑁) ↦ 𝑃)) · (𝐴 − 𝐶)) = ((𝑅 Σg (𝑘 ∈ (0..^𝑁) ↦ 𝐹)) + 𝐸))
Theorem	suppgsumssiun 33213*	The support of a function defined as a group sum is a subset of the indexed union of the supports. (Contributed by Thierry Arnoux, 16-Mar-2026.)
⊢ 𝑍 = (0g‘𝑀)    &   ⊢ (𝜑 → 𝑀 ∈ Mnd)    &   ⊢ (𝜑 → 𝐵 ∈ 𝑊)    &   ⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ (((𝜑 ∧ 𝑥 ∈ 𝐴) ∧ 𝑦 ∈ 𝐵) → 𝐶 ∈ 𝑋)    ⇒   ⊢ (𝜑 → ((𝑥 ∈ 𝐴 ↦ (𝑀 Σg (𝑦 ∈ 𝐵 ↦ 𝐶))) supp 𝑍) ⊆ ∪ 𝑦 ∈ 𝐵 ((𝑥 ∈ 𝐴 ↦ 𝐶) supp 𝑍))
Theorem	xrge0tsmsd 33214*	Any finite or infinite sum in the nonnegative extended reals is uniquely convergent to the supremum of all finite sums. (Contributed by Mario Carneiro, 13-Sep-2015.) (Revised by Thierry Arnoux, 30-Jan-2017.)
⊢ 𝐺 = (ℝ*𝑠 ↾s (0[,]+∞))    &   ⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐹:𝐴⟶(0[,]+∞))    &   ⊢ (𝜑 → 𝑆 = sup(ran (𝑠 ∈ (𝒫 𝐴 ∩ Fin) ↦ (𝐺 Σg (𝐹 ↾ 𝑠))), ℝ*, < ))    ⇒   ⊢ (𝜑 → (𝐺 tsums 𝐹) = {𝑆})
Theorem	xrge0tsmsbi 33215	Any limit of a finite or infinite sum in the nonnegative extended reals is the union of the sets limits, since this set is a singleton. (Contributed by Thierry Arnoux, 23-Jun-2017.)
⊢ 𝐺 = (ℝ*𝑠 ↾s (0[,]+∞))    &   ⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐹:𝐴⟶(0[,]+∞))    ⇒   ⊢ (𝜑 → (𝐶 ∈ (𝐺 tsums 𝐹) ↔ 𝐶 = ∪ (𝐺 tsums 𝐹)))
Theorem	xrge0tsmseq 33216	Any limit of a finite or infinite sum in the nonnegative extended reals is the union of the sets limits, since this set is a singleton. (Contributed by Thierry Arnoux, 24-Mar-2017.)
⊢ 𝐺 = (ℝ*𝑠 ↾s (0[,]+∞))    &   ⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐹:𝐴⟶(0[,]+∞))    &   ⊢ (𝜑 → 𝐶 ∈ (𝐺 tsums 𝐹))    ⇒   ⊢ (𝜑 → 𝐶 = ∪ (𝐺 tsums 𝐹))
21.3.10.6  Group or monoid sums over words
Theorem	gsumwun 33217*	In a commutative ring, a group sum of a word 𝑊 of characters taken from two submonoids 𝐸 and 𝐹 can be written as a simple sum. (Contributed by Thierry Arnoux, 6-Oct-2025.)
⊢ + = (+g‘𝑀)    &   ⊢ (𝜑 → 𝑀 ∈ CMnd)    &   ⊢ (𝜑 → 𝐸 ∈ (SubMnd‘𝑀))    &   ⊢ (𝜑 → 𝐹 ∈ (SubMnd‘𝑀))    &   ⊢ (𝜑 → 𝑊 ∈ Word (𝐸 ∪ 𝐹))    ⇒   ⊢ (𝜑 → ∃𝑒 ∈ 𝐸 ∃𝑓 ∈ 𝐹 (𝑀 Σg 𝑊) = (𝑒 + 𝑓))
Theorem	gsumwrd2dccatlem 33218*	Lemma for gsumwrd2dccat 33219. Expose a bijection 𝐹 between (ordered) pairs of words and words with a length of a subword. (Contributed by Thierry Arnoux, 5-Oct-2025.)
⊢ 𝑈 = ∪ 𝑤 ∈ Word 𝐴({𝑤} × (0...(♯‘𝑤)))    &   ⊢ 𝐹 = (𝑎 ∈ (Word 𝐴 × Word 𝐴) ↦ ⟨((1st ‘𝑎) ++ (2nd ‘𝑎)), (♯‘(1st ‘𝑎))⟩)    &   ⊢ 𝐺 = (𝑏 ∈ 𝑈 ↦ ⟨((1st ‘𝑏) prefix (2nd ‘𝑏)), ((1st ‘𝑏) substr ⟨(2nd ‘𝑏), (♯‘(1st ‘𝑏))⟩)⟩)    &   ⊢ (𝜑 → 𝐴 ∈ 𝑉)    ⇒   ⊢ (𝜑 → (𝐹:(Word 𝐴 × Word 𝐴)–1-1-onto→𝑈 ∧ ◡𝐹 = 𝐺))
Theorem	gsumwrd2dccat 33219*	Rewrite a sum ranging over pairs of words as a sum of sums over concatenated subwords. (Contributed by Thierry Arnoux, 5-Oct-2025.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ 𝑍 = (0g‘𝑀)    &   ⊢ (𝜑 → 𝐹:(Word 𝐴 × Word 𝐴)⟶𝐵)    &   ⊢ (𝜑 → 𝐹 finSupp 𝑍)    &   ⊢ (𝜑 → 𝑀 ∈ CMnd)    &   ⊢ (𝜑 → 𝐴 ⊆ 𝐵)    ⇒   ⊢ (𝜑 → (𝑀 Σg 𝐹) = (𝑀 Σg (𝑤 ∈ Word 𝐴 ↦ (𝑀 Σg (𝑗 ∈ (0...(♯‘𝑤)) ↦ (𝐹‘⟨(𝑤 prefix 𝑗), (𝑤 substr ⟨𝑗, (♯‘𝑤)⟩)⟩))))))
21.3.10.7  Centralizers and centers - misc additions
Theorem	cntzun 33220	The centralizer of a union is the intersection of the centralizers. (Contributed by Thierry Arnoux, 27-Nov-2023.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ 𝑍 = (Cntz‘𝑀)    ⇒   ⊢ ((𝑋 ⊆ 𝐵 ∧ 𝑌 ⊆ 𝐵) → (𝑍‘(𝑋 ∪ 𝑌)) = ((𝑍‘𝑋) ∩ (𝑍‘𝑌)))
Theorem	cntzsnid 33221	The centralizer of the identity element is the whole base set. (Contributed by Thierry Arnoux, 27-Nov-2023.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ 𝑍 = (Cntz‘𝑀)    &   ⊢ 0 = (0g‘𝑀)    ⇒   ⊢ (𝑀 ∈ Mnd → (𝑍‘{ 0 }) = 𝐵)
Theorem	cntrcrng 33222	The center of a ring is a commutative ring. (Contributed by Thierry Arnoux, 21-Aug-2023.)
⊢ 𝑍 = (𝑅 ↾s (Cntr‘(mulGrp‘𝑅)))    ⇒   ⊢ (𝑅 ∈ Ring → 𝑍 ∈ CRing)
21.3.10.8  The symmetric group
Theorem	symgfcoeu 33223*	Uniqueness property of permutations. (Contributed by Thierry Arnoux, 22-Aug-2020.)
⊢ 𝐺 = (Base‘(SymGrp‘𝐷))    ⇒   ⊢ ((𝐷 ∈ 𝑉 ∧ 𝑃 ∈ 𝐺 ∧ 𝑄 ∈ 𝐺) → ∃!𝑝 ∈ 𝐺 𝑄 = (𝑃 ∘ 𝑝))
Theorem	symgcom 33224	Two permutations 𝑋 and 𝑌 commute if their orbits are disjoint. (Contributed by Thierry Arnoux, 15-Oct-2023.)
⊢ 𝐺 = (SymGrp‘𝐴)    &   ⊢ 𝐵 = (Base‘𝐺)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → (𝑋 ↾ 𝐸) = ( I ↾ 𝐸))    &   ⊢ (𝜑 → (𝑌 ↾ 𝐹) = ( I ↾ 𝐹))    &   ⊢ (𝜑 → (𝐸 ∩ 𝐹) = ∅)    &   ⊢ (𝜑 → (𝐸 ∪ 𝐹) = 𝐴)    ⇒   ⊢ (𝜑 → (𝑋 ∘ 𝑌) = (𝑌 ∘ 𝑋))
Theorem	symgcom2 33225	Two permutations 𝑋 and 𝑌 commute if their orbits are disjoint. (Contributed by Thierry Arnoux, 17-Nov-2023.)
⊢ 𝐺 = (SymGrp‘𝐴)    &   ⊢ 𝐵 = (Base‘𝐺)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → (dom (𝑋 ∖ I ) ∩ dom (𝑌 ∖ I )) = ∅)    ⇒   ⊢ (𝜑 → (𝑋 ∘ 𝑌) = (𝑌 ∘ 𝑋))
Theorem	symgcntz 33226*	All elements of a (finite) set of permutations commute if their orbits are disjoint. (Contributed by Thierry Arnoux, 20-Nov-2023.)
⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝐵 = (Base‘𝑆)    &   ⊢ 𝑍 = (Cntz‘𝑆)    &   ⊢ (𝜑 → 𝐴 ⊆ 𝐵)    &   ⊢ (𝜑 → Disj 𝑥 ∈ 𝐴 dom (𝑥 ∖ I ))    ⇒   ⊢ (𝜑 → 𝐴 ⊆ (𝑍‘𝐴))
Theorem	odpmco 33227	The composition of two odd permutations is even. (Contributed by Thierry Arnoux, 15-Oct-2023.)
⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝐵 = (Base‘𝑆)    &   ⊢ 𝐴 = (pmEven‘𝐷)    ⇒   ⊢ ((𝐷 ∈ Fin ∧ 𝑋 ∈ (𝐵 ∖ 𝐴) ∧ 𝑌 ∈ (𝐵 ∖ 𝐴)) → (𝑋 ∘ 𝑌) ∈ 𝐴)
Theorem	symgsubg 33228	The value of the group subtraction operation of the symmetric group. (Contributed by Thierry Arnoux, 15-Oct-2023.)
⊢ 𝐺 = (SymGrp‘𝐴)    &   ⊢ 𝐵 = (Base‘𝐺)    &   ⊢ − = (-g‘𝐺)    ⇒   ⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → (𝑋 − 𝑌) = (𝑋 ∘ ◡𝑌))
Theorem	pmtrprfv2 33229	In a transposition of two given points, each maps to the other. (Contributed by Thierry Arnoux, 22-Aug-2020.)
⊢ 𝑇 = (pmTrsp‘𝐷)    ⇒   ⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → ((𝑇‘{𝑋, 𝑌})‘𝑌) = 𝑋)
Theorem	pmtrcnel 33230	Composing a permutation 𝐹 with a transposition which results in moving at least one less point. Here the set of points moved by a permutation 𝐹 is expressed as dom (𝐹 ∖ I ). (Contributed by Thierry Arnoux, 16-Nov-2023.)
⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑇 = (pmTrsp‘𝐷)    &   ⊢ 𝐵 = (Base‘𝑆)    &   ⊢ 𝐽 = (𝐹‘𝐼)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐹 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐼 ∈ dom (𝐹 ∖ I ))    ⇒   ⊢ (𝜑 → dom (((𝑇‘{𝐼, 𝐽}) ∘ 𝐹) ∖ I ) ⊆ (dom (𝐹 ∖ I ) ∖ {𝐼}))
Theorem	pmtrcnel2 33231	Variation on pmtrcnel 33230. (Contributed by Thierry Arnoux, 16-Nov-2023.)
⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑇 = (pmTrsp‘𝐷)    &   ⊢ 𝐵 = (Base‘𝑆)    &   ⊢ 𝐽 = (𝐹‘𝐼)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐹 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐼 ∈ dom (𝐹 ∖ I ))    ⇒   ⊢ (𝜑 → (dom (𝐹 ∖ I ) ∖ {𝐼, 𝐽}) ⊆ dom (((𝑇‘{𝐼, 𝐽}) ∘ 𝐹) ∖ I ))
Theorem	pmtrcnelor 33232	Composing a permutation 𝐹 with a transposition which results in moving one or two less points. (Contributed by Thierry Arnoux, 16-Nov-2023.)
⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑇 = (pmTrsp‘𝐷)    &   ⊢ 𝐵 = (Base‘𝑆)    &   ⊢ 𝐽 = (𝐹‘𝐼)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐹 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐼 ∈ dom (𝐹 ∖ I ))    &   ⊢ 𝐸 = dom (𝐹 ∖ I )    &   ⊢ 𝐴 = dom (((𝑇‘{𝐼, 𝐽}) ∘ 𝐹) ∖ I )    ⇒   ⊢ (𝜑 → (𝐴 = (𝐸 ∖ {𝐼, 𝐽}) ∨ 𝐴 = (𝐸 ∖ {𝐼})))
Theorem	fzo0pmtrlast 33233*	Reorder a half-open integer range based at 0, so that the given index 𝐼 is at the end. (Contributed by Thierry Arnoux, 27-May-2025.)
⊢ 𝐽 = (0..^𝑁)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐽)    ⇒   ⊢ (𝜑 → ∃𝑠(𝑠:𝐽–1-1-onto→𝐽 ∧ (𝑠‘(𝑁 − 1)) = 𝐼))
Theorem	wrdpmtrlast 33234*	Reorder a word, so that the symbol given at index 𝐼 is at the end. (Contributed by Thierry Arnoux, 27-May-2025.)
⊢ 𝐽 = (0..^(♯‘𝑊))    &   ⊢ (𝜑 → 𝐼 ∈ 𝐽)    &   ⊢ (𝜑 → 𝑊 ∈ Word 𝑆)    &   ⊢ 𝑈 = ((𝑊 ∘ 𝑠) prefix ((♯‘𝑊) − 1))    ⇒   ⊢ (𝜑 → ∃𝑠(𝑠:𝐽–1-1-onto→𝐽 ∧ (𝑊 ∘ 𝑠) = (𝑈 ++ ⟨“(𝑊‘𝐼)”⟩)))
21.3.10.9  Transpositions
Theorem	pmtridf1o 33235	Transpositions of 𝑋 and 𝑌 (understood to be the identity when 𝑋 = 𝑌), are bijections. (Contributed by Thierry Arnoux, 1-Jan-2022.)
⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐴)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐴)    &   ⊢ 𝑇 = if(𝑋 = 𝑌, ( I ↾ 𝐴), ((pmTrsp‘𝐴)‘{𝑋, 𝑌}))    ⇒   ⊢ (𝜑 → 𝑇:𝐴–1-1-onto→𝐴)
Theorem	pmtridfv1 33236	Value at X of the transposition of 𝑋 and 𝑌 (understood to be the identity when X = Y ). (Contributed by Thierry Arnoux, 3-Jan-2022.)
⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐴)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐴)    &   ⊢ 𝑇 = if(𝑋 = 𝑌, ( I ↾ 𝐴), ((pmTrsp‘𝐴)‘{𝑋, 𝑌}))    ⇒   ⊢ (𝜑 → (𝑇‘𝑋) = 𝑌)
Theorem	pmtridfv2 33237	Value at Y of the transposition of 𝑋 and 𝑌 (understood to be the identity when X = Y ). (Contributed by Thierry Arnoux, 3-Jan-2022.)
⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐴)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐴)    &   ⊢ 𝑇 = if(𝑋 = 𝑌, ( I ↾ 𝐴), ((pmTrsp‘𝐴)‘{𝑋, 𝑌}))    ⇒   ⊢ (𝜑 → (𝑇‘𝑌) = 𝑋)
21.3.10.10  Permutation Signs
Theorem	psgnid 33238	Permutation sign of the identity. (Contributed by Thierry Arnoux, 21-Aug-2020.)
⊢ 𝑆 = (pmSgn‘𝐷)    ⇒   ⊢ (𝐷 ∈ Fin → (𝑆‘( I ↾ 𝐷)) = 1)
Theorem	psgndmfi 33239	For a finite base set, the permutation sign is defined for all permutations. (Contributed by Thierry Arnoux, 22-Aug-2020.)
⊢ 𝑆 = (pmSgn‘𝐷)    &   ⊢ 𝐺 = (Base‘(SymGrp‘𝐷))    ⇒   ⊢ (𝐷 ∈ Fin → 𝑆 Fn 𝐺)
Theorem	pmtrto1cl 33240	Useful lemma for the following theorems. (Contributed by Thierry Arnoux, 21-Aug-2020.)
⊢ 𝐷 = (1...𝑁)    &   ⊢ 𝑇 = (pmTrsp‘𝐷)    ⇒   ⊢ ((𝐾 ∈ ℕ ∧ (𝐾 + 1) ∈ 𝐷) → (𝑇‘{𝐾, (𝐾 + 1)}) ∈ ran 𝑇)
Theorem	psgnfzto1stlem 33241*	Lemma for psgnfzto1st 33246. Our permutation of rank (𝑛 + 1) can be written as a permutation of rank 𝑛 composed with a transposition. (Contributed by Thierry Arnoux, 21-Aug-2020.)
⊢ 𝐷 = (1...𝑁)    ⇒   ⊢ ((𝐾 ∈ ℕ ∧ (𝐾 + 1) ∈ 𝐷) → (𝑖 ∈ 𝐷 ↦ if(𝑖 = 1, (𝐾 + 1), if(𝑖 ≤ (𝐾 + 1), (𝑖 − 1), 𝑖))) = (((pmTrsp‘𝐷)‘{𝐾, (𝐾 + 1)}) ∘ (𝑖 ∈ 𝐷 ↦ if(𝑖 = 1, 𝐾, if(𝑖 ≤ 𝐾, (𝑖 − 1), 𝑖)))))
Theorem	fzto1stfv1 33242*	Value of our permutation 𝑃 at 1. (Contributed by Thierry Arnoux, 23-Aug-2020.)
⊢ 𝐷 = (1...𝑁)    &   ⊢ 𝑃 = (𝑖 ∈ 𝐷 ↦ if(𝑖 = 1, 𝐼, if(𝑖 ≤ 𝐼, (𝑖 − 1), 𝑖)))    ⇒   ⊢ (𝐼 ∈ 𝐷 → (𝑃‘1) = 𝐼)
Theorem	fzto1st1 33243*	Special case where the permutation defined in psgnfzto1st 33246 is the identity. (Contributed by Thierry Arnoux, 21-Aug-2020.)
⊢ 𝐷 = (1...𝑁)    &   ⊢ 𝑃 = (𝑖 ∈ 𝐷 ↦ if(𝑖 = 1, 𝐼, if(𝑖 ≤ 𝐼, (𝑖 − 1), 𝑖)))    ⇒   ⊢ (𝐼 = 1 → 𝑃 = ( I ↾ 𝐷))
Theorem	fzto1st 33244*	The function moving one element to the first position (and shifting all elements before it) is a permutation. (Contributed by Thierry Arnoux, 21-Aug-2020.)
⊢ 𝐷 = (1...𝑁)    &   ⊢ 𝑃 = (𝑖 ∈ 𝐷 ↦ if(𝑖 = 1, 𝐼, if(𝑖 ≤ 𝐼, (𝑖 − 1), 𝑖)))    &   ⊢ 𝐺 = (SymGrp‘𝐷)    &   ⊢ 𝐵 = (Base‘𝐺)    ⇒   ⊢ (𝐼 ∈ 𝐷 → 𝑃 ∈ 𝐵)
Theorem	fzto1stinvn 33245*	Value of the inverse of our permutation 𝑃 at 𝐼. (Contributed by Thierry Arnoux, 23-Aug-2020.)
⊢ 𝐷 = (1...𝑁)    &   ⊢ 𝑃 = (𝑖 ∈ 𝐷 ↦ if(𝑖 = 1, 𝐼, if(𝑖 ≤ 𝐼, (𝑖 − 1), 𝑖)))    &   ⊢ 𝐺 = (SymGrp‘𝐷)    &   ⊢ 𝐵 = (Base‘𝐺)    ⇒   ⊢ (𝐼 ∈ 𝐷 → (◡𝑃‘𝐼) = 1)
Theorem	psgnfzto1st 33246*	The permutation sign for moving one element to the first position. (Contributed by Thierry Arnoux, 21-Aug-2020.)
⊢ 𝐷 = (1...𝑁)    &   ⊢ 𝑃 = (𝑖 ∈ 𝐷 ↦ if(𝑖 = 1, 𝐼, if(𝑖 ≤ 𝐼, (𝑖 − 1), 𝑖)))    &   ⊢ 𝐺 = (SymGrp‘𝐷)    &   ⊢ 𝐵 = (Base‘𝐺)    &   ⊢ 𝑆 = (pmSgn‘𝐷)    ⇒   ⊢ (𝐼 ∈ 𝐷 → (𝑆‘𝑃) = (-1↑(𝐼 + 1)))
21.3.10.11  Permutation cycles
Syntax	ctocyc 33247	Extend class notation with the permutation cycle builder.
class toCyc
Definition	df-tocyc 33248*	Define a convenience permutation cycle builder. Given a list of elements to be cycled, in the form of a word, this function produces the corresponding permutation cycle. See definition in [Lang] p. 30. (Contributed by Thierry Arnoux, 19-Sep-2023.)
⊢ toCyc = (𝑑 ∈ V ↦ (𝑤 ∈ {𝑢 ∈ Word 𝑑 ∣ 𝑢:dom 𝑢–1-1→𝑑} ↦ (( I ↾ (𝑑 ∖ ran 𝑤)) ∪ ((𝑤 cyclShift 1) ∘ ◡𝑤))))
Theorem	tocycval 33249*	Value of the cycle builder. (Contributed by Thierry Arnoux, 22-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    ⇒   ⊢ (𝐷 ∈ 𝑉 → 𝐶 = (𝑤 ∈ {𝑢 ∈ Word 𝐷 ∣ 𝑢:dom 𝑢–1-1→𝐷} ↦ (( I ↾ (𝐷 ∖ ran 𝑤)) ∪ ((𝑤 cyclShift 1) ∘ ◡𝑤))))
Theorem	tocycfv 33250	Function value of a permutation cycle built from a word. (Contributed by Thierry Arnoux, 18-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ Word 𝐷)    &   ⊢ (𝜑 → 𝑊:dom 𝑊–1-1→𝐷)    ⇒   ⊢ (𝜑 → (𝐶‘𝑊) = (( I ↾ (𝐷 ∖ ran 𝑊)) ∪ ((𝑊 cyclShift 1) ∘ ◡𝑊)))
Theorem	tocycfvres1 33251	A cyclic permutation is a cyclic shift on its orbit. (Contributed by Thierry Arnoux, 15-Oct-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ Word 𝐷)    &   ⊢ (𝜑 → 𝑊:dom 𝑊–1-1→𝐷)    ⇒   ⊢ (𝜑 → ((𝐶‘𝑊) ↾ ran 𝑊) = ((𝑊 cyclShift 1) ∘ ◡𝑊))
Theorem	tocycfvres2 33252	A cyclic permutation is the identity outside of its orbit. (Contributed by Thierry Arnoux, 15-Oct-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ Word 𝐷)    &   ⊢ (𝜑 → 𝑊:dom 𝑊–1-1→𝐷)    ⇒   ⊢ (𝜑 → ((𝐶‘𝑊) ↾ (𝐷 ∖ ran 𝑊)) = ( I ↾ (𝐷 ∖ ran 𝑊)))
Theorem	cycpmfvlem 33253	Lemma for cycpmfv1 33254 and cycpmfv2 33255. (Contributed by Thierry Arnoux, 22-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ Word 𝐷)    &   ⊢ (𝜑 → 𝑊:dom 𝑊–1-1→𝐷)    &   ⊢ (𝜑 → 𝑁 ∈ (0..^(♯‘𝑊)))    ⇒   ⊢ (𝜑 → ((𝐶‘𝑊)‘(𝑊‘𝑁)) = (((𝑊 cyclShift 1) ∘ ◡𝑊)‘(𝑊‘𝑁)))
Theorem	cycpmfv1 33254	Value of a cycle function for any element but the last. (Contributed by Thierry Arnoux, 22-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ Word 𝐷)    &   ⊢ (𝜑 → 𝑊:dom 𝑊–1-1→𝐷)    &   ⊢ (𝜑 → 𝑁 ∈ (0..^((♯‘𝑊) − 1)))    ⇒   ⊢ (𝜑 → ((𝐶‘𝑊)‘(𝑊‘𝑁)) = (𝑊‘(𝑁 + 1)))
Theorem	cycpmfv2 33255	Value of a cycle function for the last element of the orbit. (Contributed by Thierry Arnoux, 22-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ Word 𝐷)    &   ⊢ (𝜑 → 𝑊:dom 𝑊–1-1→𝐷)    &   ⊢ (𝜑 → 0 < (♯‘𝑊))    &   ⊢ (𝜑 → 𝑁 = ((♯‘𝑊) − 1))    ⇒   ⊢ (𝜑 → ((𝐶‘𝑊)‘(𝑊‘𝑁)) = (𝑊‘0))
Theorem	cycpmfv3 33256	Values outside of the orbit are unchanged by a cycle. (Contributed by Thierry Arnoux, 22-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ Word 𝐷)    &   ⊢ (𝜑 → 𝑊:dom 𝑊–1-1→𝐷)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐷)    &   ⊢ (𝜑 → ¬ 𝑋 ∈ ran 𝑊)    ⇒   ⊢ (𝜑 → ((𝐶‘𝑊)‘𝑋) = 𝑋)
Theorem	cycpmcl 33257	Cyclic permutations are permutations. (Contributed by Thierry Arnoux, 24-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ Word 𝐷)    &   ⊢ (𝜑 → 𝑊:dom 𝑊–1-1→𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    ⇒   ⊢ (𝜑 → (𝐶‘𝑊) ∈ (Base‘𝑆))
Theorem	tocycf 33258*	The permutation cycle builder as a function. (Contributed by Thierry Arnoux, 25-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝐵 = (Base‘𝑆)    ⇒   ⊢ (𝐷 ∈ 𝑉 → 𝐶:{𝑤 ∈ Word 𝐷 ∣ 𝑤:dom 𝑤–1-1→𝐷}⟶𝐵)
Theorem	tocyc01 33259	Permutation cycles built from the empty set or a singleton are the identity. (Contributed by Thierry Arnoux, 21-Nov-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    ⇒   ⊢ ((𝐷 ∈ 𝑉 ∧ 𝑊 ∈ (dom 𝐶 ∩ (◡♯ “ {0, 1}))) → (𝐶‘𝑊) = ( I ↾ 𝐷))
Theorem	cycpm2tr 33260	A cyclic permutation of 2 elements is a transposition. (Contributed by Thierry Arnoux, 24-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ 𝑇 = (pmTrsp‘𝐷)    ⇒   ⊢ (𝜑 → (𝐶‘⟨“𝐼𝐽”⟩) = (𝑇‘{𝐼, 𝐽}))
Theorem	cycpm2cl 33261	Closure for the 2-cycles. (Contributed by Thierry Arnoux, 24-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    ⇒   ⊢ (𝜑 → (𝐶‘⟨“𝐼𝐽”⟩) ∈ (Base‘𝑆))
Theorem	cyc2fv1 33262	Function value of a 2-cycle at the first point. (Contributed by Thierry Arnoux, 24-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    ⇒   ⊢ (𝜑 → ((𝐶‘⟨“𝐼𝐽”⟩)‘𝐼) = 𝐽)
Theorem	cyc2fv2 33263	Function value of a 2-cycle at the second point. (Contributed by Thierry Arnoux, 24-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    ⇒   ⊢ (𝜑 → ((𝐶‘⟨“𝐼𝐽”⟩)‘𝐽) = 𝐼)
Theorem	trsp2cyc 33264*	Exhibit the word a transposition corresponds to, as a cycle. (Contributed by Thierry Arnoux, 25-Sep-2023.)
⊢ 𝑇 = ran (pmTrsp‘𝐷)    &   ⊢ 𝐶 = (toCyc‘𝐷)    ⇒   ⊢ ((𝐷 ∈ 𝑉 ∧ 𝑃 ∈ 𝑇) → ∃𝑖 ∈ 𝐷 ∃𝑗 ∈ 𝐷 (𝑖 ≠ 𝑗 ∧ 𝑃 = (𝐶‘⟨“𝑖𝑗”⟩)))
Theorem	cycpmco2f1 33265	The word U used in cycpmco2 33274 is injective, so it can represent a cycle and form a cyclic permutation (𝑀‘𝑈). (Contributed by Thierry Arnoux, 4-Jan-2024.)
⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ dom 𝑀)    &   ⊢ (𝜑 → 𝐼 ∈ (𝐷 ∖ ran 𝑊))    &   ⊢ (𝜑 → 𝐽 ∈ ran 𝑊)    &   ⊢ 𝐸 = ((◡𝑊‘𝐽) + 1)    &   ⊢ 𝑈 = (𝑊 splice ⟨𝐸, 𝐸, ⟨“𝐼”⟩⟩)    ⇒   ⊢ (𝜑 → 𝑈:dom 𝑈–1-1→𝐷)
Theorem	cycpmco2rn 33266	The orbit of the composition of a cyclic permutation and a well-chosen transposition is one element more than the orbit of the original permutation. (Contributed by Thierry Arnoux, 4-Jan-2024.)
⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ dom 𝑀)    &   ⊢ (𝜑 → 𝐼 ∈ (𝐷 ∖ ran 𝑊))    &   ⊢ (𝜑 → 𝐽 ∈ ran 𝑊)    &   ⊢ 𝐸 = ((◡𝑊‘𝐽) + 1)    &   ⊢ 𝑈 = (𝑊 splice ⟨𝐸, 𝐸, ⟨“𝐼”⟩⟩)    ⇒   ⊢ (𝜑 → ran 𝑈 = (ran 𝑊 ∪ {𝐼}))
Theorem	cycpmco2lem1 33267	Lemma for cycpmco2 33274. (Contributed by Thierry Arnoux, 4-Jan-2024.)
⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ dom 𝑀)    &   ⊢ (𝜑 → 𝐼 ∈ (𝐷 ∖ ran 𝑊))    &   ⊢ (𝜑 → 𝐽 ∈ ran 𝑊)    &   ⊢ 𝐸 = ((◡𝑊‘𝐽) + 1)    &   ⊢ 𝑈 = (𝑊 splice ⟨𝐸, 𝐸, ⟨“𝐼”⟩⟩)    ⇒   ⊢ (𝜑 → ((𝑀‘𝑊)‘((𝑀‘⟨“𝐼𝐽”⟩)‘𝐼)) = ((𝑀‘𝑊)‘𝐽))
Theorem	cycpmco2lem2 33268	Lemma for cycpmco2 33274. (Contributed by Thierry Arnoux, 4-Jan-2024.)
⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ dom 𝑀)    &   ⊢ (𝜑 → 𝐼 ∈ (𝐷 ∖ ran 𝑊))    &   ⊢ (𝜑 → 𝐽 ∈ ran 𝑊)    &   ⊢ 𝐸 = ((◡𝑊‘𝐽) + 1)    &   ⊢ 𝑈 = (𝑊 splice ⟨𝐸, 𝐸, ⟨“𝐼”⟩⟩)    ⇒   ⊢ (𝜑 → (𝑈‘𝐸) = 𝐼)
Theorem	cycpmco2lem3 33269	Lemma for cycpmco2 33274. (Contributed by Thierry Arnoux, 4-Jan-2024.)
⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ dom 𝑀)    &   ⊢ (𝜑 → 𝐼 ∈ (𝐷 ∖ ran 𝑊))    &   ⊢ (𝜑 → 𝐽 ∈ ran 𝑊)    &   ⊢ 𝐸 = ((◡𝑊‘𝐽) + 1)    &   ⊢ 𝑈 = (𝑊 splice ⟨𝐸, 𝐸, ⟨“𝐼”⟩⟩)    ⇒   ⊢ (𝜑 → ((♯‘𝑈) − 1) = (♯‘𝑊))
Theorem	cycpmco2lem4 33270	Lemma for cycpmco2 33274. (Contributed by Thierry Arnoux, 4-Jan-2024.)
⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ dom 𝑀)    &   ⊢ (𝜑 → 𝐼 ∈ (𝐷 ∖ ran 𝑊))    &   ⊢ (𝜑 → 𝐽 ∈ ran 𝑊)    &   ⊢ 𝐸 = ((◡𝑊‘𝐽) + 1)    &   ⊢ 𝑈 = (𝑊 splice ⟨𝐸, 𝐸, ⟨“𝐼”⟩⟩)    ⇒   ⊢ (𝜑 → ((𝑀‘𝑊)‘((𝑀‘⟨“𝐼𝐽”⟩)‘𝐼)) = ((𝑀‘𝑈)‘𝐼))
Theorem	cycpmco2lem5 33271	Lemma for cycpmco2 33274. (Contributed by Thierry Arnoux, 4-Jan-2024.)
⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ dom 𝑀)    &   ⊢ (𝜑 → 𝐼 ∈ (𝐷 ∖ ran 𝑊))    &   ⊢ (𝜑 → 𝐽 ∈ ran 𝑊)    &   ⊢ 𝐸 = ((◡𝑊‘𝐽) + 1)    &   ⊢ 𝑈 = (𝑊 splice ⟨𝐸, 𝐸, ⟨“𝐼”⟩⟩)    &   ⊢ (𝜑 → 𝐾 ∈ ran 𝑊)    &   ⊢ (𝜑 → (◡𝑈‘𝐾) = ((♯‘𝑈) − 1))    ⇒   ⊢ (𝜑 → ((𝑀‘𝑈)‘𝐾) = ((𝑀‘𝑊)‘𝐾))
Theorem	cycpmco2lem6 33272	Lemma for cycpmco2 33274. (Contributed by Thierry Arnoux, 4-Jan-2024.)
⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ dom 𝑀)    &   ⊢ (𝜑 → 𝐼 ∈ (𝐷 ∖ ran 𝑊))    &   ⊢ (𝜑 → 𝐽 ∈ ran 𝑊)    &   ⊢ 𝐸 = ((◡𝑊‘𝐽) + 1)    &   ⊢ 𝑈 = (𝑊 splice ⟨𝐸, 𝐸, ⟨“𝐼”⟩⟩)    &   ⊢ (𝜑 → 𝐾 ∈ ran 𝑊)    &   ⊢ (𝜑 → 𝐾 ≠ 𝐼)    &   ⊢ (𝜑 → (◡𝑈‘𝐾) ∈ (𝐸..^((♯‘𝑈) − 1)))    ⇒   ⊢ (𝜑 → ((𝑀‘𝑈)‘𝐾) = ((𝑀‘𝑊)‘𝐾))
Theorem	cycpmco2lem7 33273	Lemma for cycpmco2 33274. (Contributed by Thierry Arnoux, 4-Jan-2024.)
⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ dom 𝑀)    &   ⊢ (𝜑 → 𝐼 ∈ (𝐷 ∖ ran 𝑊))    &   ⊢ (𝜑 → 𝐽 ∈ ran 𝑊)    &   ⊢ 𝐸 = ((◡𝑊‘𝐽) + 1)    &   ⊢ 𝑈 = (𝑊 splice ⟨𝐸, 𝐸, ⟨“𝐼”⟩⟩)    &   ⊢ (𝜑 → 𝐾 ∈ ran 𝑊)    &   ⊢ (𝜑 → 𝐾 ≠ 𝐽)    &   ⊢ (𝜑 → (◡𝑈‘𝐾) ∈ (0..^𝐸))    ⇒   ⊢ (𝜑 → ((𝑀‘𝑈)‘𝐾) = ((𝑀‘𝑊)‘𝐾))
Theorem	cycpmco2 33274	The composition of a cyclic permutation and a transposition of one element in the cycle and one outside the cycle results in a cyclic permutation with one more element in its orbit. (Contributed by Thierry Arnoux, 2-Jan-2024.)
⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ dom 𝑀)    &   ⊢ (𝜑 → 𝐼 ∈ (𝐷 ∖ ran 𝑊))    &   ⊢ (𝜑 → 𝐽 ∈ ran 𝑊)    &   ⊢ 𝐸 = ((◡𝑊‘𝐽) + 1)    &   ⊢ 𝑈 = (𝑊 splice ⟨𝐸, 𝐸, ⟨“𝐼”⟩⟩)    ⇒   ⊢ (𝜑 → ((𝑀‘𝑊) ∘ (𝑀‘⟨“𝐼𝐽”⟩)) = (𝑀‘𝑈))
Theorem	cyc2fvx 33275	Function value of a 2-cycle outside of its orbit. (Contributed by Thierry Arnoux, 19-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐾 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ (𝜑 → 𝐽 ≠ 𝐾)    &   ⊢ (𝜑 → 𝐾 ≠ 𝐼)    ⇒   ⊢ (𝜑 → ((𝐶‘⟨“𝐼𝐽”⟩)‘𝐾) = 𝐾)
Theorem	cycpm3cl 33276	Closure of the 3-cycles in the permutations. (Contributed by Thierry Arnoux, 19-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐾 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ (𝜑 → 𝐽 ≠ 𝐾)    &   ⊢ (𝜑 → 𝐾 ≠ 𝐼)    ⇒   ⊢ (𝜑 → (𝐶‘⟨“𝐼𝐽𝐾”⟩) ∈ (Base‘𝑆))
Theorem	cycpm3cl2 33277	Closure of the 3-cycles in the class of 3-cycles. (Contributed by Thierry Arnoux, 19-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐾 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ (𝜑 → 𝐽 ≠ 𝐾)    &   ⊢ (𝜑 → 𝐾 ≠ 𝐼)    ⇒   ⊢ (𝜑 → (𝐶‘⟨“𝐼𝐽𝐾”⟩) ∈ (𝐶 “ (◡♯ “ {3})))
Theorem	cyc3fv1 33278	Function value of a 3-cycle at the first point. (Contributed by Thierry Arnoux, 19-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐾 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ (𝜑 → 𝐽 ≠ 𝐾)    &   ⊢ (𝜑 → 𝐾 ≠ 𝐼)    ⇒   ⊢ (𝜑 → ((𝐶‘⟨“𝐼𝐽𝐾”⟩)‘𝐼) = 𝐽)
Theorem	cyc3fv2 33279	Function value of a 3-cycle at the second point. (Contributed by Thierry Arnoux, 19-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐾 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ (𝜑 → 𝐽 ≠ 𝐾)    &   ⊢ (𝜑 → 𝐾 ≠ 𝐼)    ⇒   ⊢ (𝜑 → ((𝐶‘⟨“𝐼𝐽𝐾”⟩)‘𝐽) = 𝐾)
Theorem	cyc3fv3 33280	Function value of a 3-cycle at the third point. (Contributed by Thierry Arnoux, 19-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐾 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ (𝜑 → 𝐽 ≠ 𝐾)    &   ⊢ (𝜑 → 𝐾 ≠ 𝐼)    ⇒   ⊢ (𝜑 → ((𝐶‘⟨“𝐼𝐽𝐾”⟩)‘𝐾) = 𝐼)
Theorem	cyc3co2 33281	Represent a 3-cycle as a composition of two 2-cycles. (Contributed by Thierry Arnoux, 19-Sep-2023.)
⊢ 𝐶 = (toCyc‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐾 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ (𝜑 → 𝐽 ≠ 𝐾)    &   ⊢ (𝜑 → 𝐾 ≠ 𝐼)    &   ⊢ · = (+g‘𝑆)    ⇒   ⊢ (𝜑 → (𝐶‘⟨“𝐼𝐽𝐾”⟩) = ((𝐶‘⟨“𝐼𝐾”⟩) · (𝐶‘⟨“𝐼𝐽”⟩)))
Theorem	cycpmconjvlem 33282	Lemma for cycpmconjv 33283. (Contributed by Thierry Arnoux, 9-Oct-2023.)
⊢ (𝜑 → 𝐹:𝐷–1-1-onto→𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐷)    ⇒   ⊢ (𝜑 → ((𝐹 ↾ (𝐷 ∖ 𝐵)) ∘ ◡𝐹) = ( I ↾ (𝐷 ∖ ran (𝐹 ↾ 𝐵))))
Theorem	cycpmconjv 33283	A formula for computing conjugacy classes of cyclic permutations. Formula in property (b) of [Lang] p. 32. (Contributed by Thierry Arnoux, 9-Oct-2023.)
⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ + = (+g‘𝑆)    &   ⊢ − = (-g‘𝑆)    &   ⊢ 𝐵 = (Base‘𝑆)    ⇒   ⊢ ((𝐷 ∈ 𝑉 ∧ 𝐺 ∈ 𝐵 ∧ 𝑊 ∈ dom 𝑀) → ((𝐺 + (𝑀‘𝑊)) − 𝐺) = (𝑀‘(𝐺 ∘ 𝑊)))
Theorem	cycpmrn 33284	The range of the word used to build a cycle is the cycle's orbit, i.e., the set of points it moves. (Contributed by Thierry Arnoux, 20-Nov-2023.)
⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ Word 𝐷)    &   ⊢ (𝜑 → 𝑊:dom 𝑊–1-1→𝐷)    &   ⊢ (𝜑 → 1 < (♯‘𝑊))    ⇒   ⊢ (𝜑 → ran 𝑊 = dom ((𝑀‘𝑊) ∖ I ))
Theorem	tocyccntz 33285*	All elements of a (finite) set of cycles commute if their orbits are disjoint. (Contributed by Thierry Arnoux, 27-Nov-2023.)
⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑍 = (Cntz‘𝑆)    &   ⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → Disj 𝑥 ∈ 𝐴 ran 𝑥)    &   ⊢ (𝜑 → 𝐴 ⊆ dom 𝑀)    ⇒   ⊢ (𝜑 → (𝑀 “ 𝐴) ⊆ (𝑍‘(𝑀 “ 𝐴)))
21.3.10.12  The Alternating Group
Theorem	evpmval 33286	Value of the set of even permutations, the alternating group. (Contributed by Thierry Arnoux, 1-Nov-2023.)
⊢ 𝐴 = (pmEven‘𝐷)    ⇒   ⊢ (𝐷 ∈ 𝑉 → 𝐴 = (◡(pmSgn‘𝐷) “ {1}))
Theorem	cnmsgn0g 33287	The neutral element of the sign subgroup of the complex numbers. (Contributed by Thierry Arnoux, 1-Nov-2023.)
⊢ 𝑈 = ((mulGrp‘ℂfld) ↾s {1, -1})    ⇒   ⊢ 1 = (0g‘𝑈)
Theorem	evpmsubg 33288	The alternating group is a subgroup of the symmetric group. (Contributed by Thierry Arnoux, 1-Nov-2023.)
⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝐴 = (pmEven‘𝐷)    ⇒   ⊢ (𝐷 ∈ Fin → 𝐴 ∈ (SubGrp‘𝑆))
Theorem	evpmid 33289	The identity is an even permutation. (Contributed by Thierry Arnoux, 18-Sep-2023.)
⊢ 𝑆 = (SymGrp‘𝐷)    ⇒   ⊢ (𝐷 ∈ Fin → ( I ↾ 𝐷) ∈ (pmEven‘𝐷))
Theorem	altgnsg 33290	The alternating group (pmEven‘𝐷) is a normal subgroup of the symmetric group. (Contributed by Thierry Arnoux, 18-Sep-2023.)
⊢ 𝑆 = (SymGrp‘𝐷)    ⇒   ⊢ (𝐷 ∈ Fin → (pmEven‘𝐷) ∈ (NrmSGrp‘𝑆))
Theorem	cyc3evpm 33291	3-Cycles are even permutations. (Contributed by Thierry Arnoux, 24-Sep-2023.)
⊢ 𝐶 = ((toCyc‘𝐷) “ (◡♯ “ {3}))    &   ⊢ 𝐴 = (pmEven‘𝐷)    ⇒   ⊢ (𝐷 ∈ Fin → 𝐶 ⊆ 𝐴)
Theorem	cyc3genpmlem 33292*	Lemma for cyc3genpm 33293. (Contributed by Thierry Arnoux, 24-Sep-2023.)
⊢ 𝐶 = (𝑀 “ (◡♯ “ {3}))    &   ⊢ 𝐴 = (pmEven‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑁 = (♯‘𝐷)    &   ⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ · = (+g‘𝑆)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐾 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐿 ∈ 𝐷)    &   ⊢ (𝜑 → 𝐸 = (𝑀‘⟨“𝐼𝐽”⟩))    &   ⊢ (𝜑 → 𝐹 = (𝑀‘⟨“𝐾𝐿”⟩))    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ≠ 𝐽)    &   ⊢ (𝜑 → 𝐾 ≠ 𝐿)    ⇒   ⊢ (𝜑 → ∃𝑐 ∈ Word 𝐶(𝐸 · 𝐹) = (𝑆 Σg 𝑐))
Theorem	cyc3genpm 33293*	The alternating group 𝐴 is generated by 3-cycles. Property (a) of [Lang] p. 32 . (Contributed by Thierry Arnoux, 27-Sep-2023.)
⊢ 𝐶 = (𝑀 “ (◡♯ “ {3}))    &   ⊢ 𝐴 = (pmEven‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑁 = (♯‘𝐷)    &   ⊢ 𝑀 = (toCyc‘𝐷)    ⇒   ⊢ (𝐷 ∈ Fin → (𝑄 ∈ 𝐴 ↔ ∃𝑤 ∈ Word 𝐶𝑄 = (𝑆 Σg 𝑤)))
Theorem	cycpmgcl 33294	Cyclic permutations are permutations, similar to cycpmcl 33257, but where the set of cyclic permutations of length 𝑃 is expressed in terms of a preimage. (Contributed by Thierry Arnoux, 13-Oct-2023.)
⊢ 𝐶 = (𝑀 “ (◡♯ “ {𝑃}))    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑁 = (♯‘𝐷)    &   ⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝐵 = (Base‘𝑆)    ⇒   ⊢ ((𝐷 ∈ 𝑉 ∧ 𝑃 ∈ (0...𝑁)) → 𝐶 ⊆ 𝐵)
Theorem	cycpmconjslem1 33295	Lemma for cycpmconjs 33297. (Contributed by Thierry Arnoux, 14-Oct-2023.)
⊢ 𝐶 = (𝑀 “ (◡♯ “ {𝑃}))    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑁 = (♯‘𝐷)    &   ⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ (𝜑 → 𝐷 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑊 ∈ Word 𝐷)    &   ⊢ (𝜑 → 𝑊:dom 𝑊–1-1→𝐷)    &   ⊢ (𝜑 → (♯‘𝑊) = 𝑃)    ⇒   ⊢ (𝜑 → ((◡𝑊 ∘ (𝑀‘𝑊)) ∘ 𝑊) = (( I ↾ (0..^𝑃)) cyclShift 1))
Theorem	cycpmconjslem2 33296*	Lemma for cycpmconjs 33297. (Contributed by Thierry Arnoux, 14-Oct-2023.)
⊢ 𝐶 = (𝑀 “ (◡♯ “ {𝑃}))    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑁 = (♯‘𝐷)    &   ⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝐵 = (Base‘𝑆)    &   ⊢ + = (+g‘𝑆)    &   ⊢ − = (-g‘𝑆)    &   ⊢ (𝜑 → 𝑃 ∈ (0...𝑁))    &   ⊢ (𝜑 → 𝐷 ∈ Fin)    &   ⊢ (𝜑 → 𝑄 ∈ 𝐶)    ⇒   ⊢ (𝜑 → ∃𝑞(𝑞:(0..^𝑁)–1-1-onto→𝐷 ∧ ((◡𝑞 ∘ 𝑄) ∘ 𝑞) = ((( I ↾ (0..^𝑃)) cyclShift 1) ∪ ( I ↾ (𝑃..^𝑁)))))
Theorem	cycpmconjs 33297*	All cycles of the same length are conjugate in the symmetric group. (Contributed by Thierry Arnoux, 14-Oct-2023.)
⊢ 𝐶 = (𝑀 “ (◡♯ “ {𝑃}))    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑁 = (♯‘𝐷)    &   ⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ 𝐵 = (Base‘𝑆)    &   ⊢ + = (+g‘𝑆)    &   ⊢ − = (-g‘𝑆)    &   ⊢ (𝜑 → 𝑃 ∈ (0...𝑁))    &   ⊢ (𝜑 → 𝐷 ∈ Fin)    &   ⊢ (𝜑 → 𝑄 ∈ 𝐶)    &   ⊢ (𝜑 → 𝑇 ∈ 𝐶)    ⇒   ⊢ (𝜑 → ∃𝑝 ∈ 𝐵 𝑄 = ((𝑝 + 𝑇) − 𝑝))
Theorem	cyc3conja 33298*	All 3-cycles are conjugate in the alternating group An for n>= 5. Property (b) of [Lang] p. 32. (Contributed by Thierry Arnoux, 15-Oct-2023.)
⊢ 𝐶 = (𝑀 “ (◡♯ “ {3}))    &   ⊢ 𝐴 = (pmEven‘𝐷)    &   ⊢ 𝑆 = (SymGrp‘𝐷)    &   ⊢ 𝑁 = (♯‘𝐷)    &   ⊢ 𝑀 = (toCyc‘𝐷)    &   ⊢ + = (+g‘𝑆)    &   ⊢ − = (-g‘𝑆)    &   ⊢ (𝜑 → 5 ≤ 𝑁)    &   ⊢ (𝜑 → 𝐷 ∈ Fin)    &   ⊢ (𝜑 → 𝑄 ∈ 𝐶)    &   ⊢ (𝜑 → 𝑇 ∈ 𝐶)    ⇒   ⊢ (𝜑 → ∃𝑝 ∈ 𝐴 𝑄 = ((𝑝 + 𝑇) − 𝑝))
21.3.10.13  Signum in an ordered monoid
Syntax	csgns 33299	Extend class notation to include the Signum function.
class sgns
Definition	df-sgns 33300*	Signum function for a structure. See also df-sgn 15097 for the version for extended reals. (Contributed by Thierry Arnoux, 10-Sep-2018.)
⊢ sgns = (𝑟 ∈ V ↦ (𝑥 ∈ (Base‘𝑟) ↦ if(𝑥 = (0g‘𝑟), 0, if((0g‘𝑟)(lt‘𝑟)𝑥, 1, -1))))