P. 328 of Theorem List - Metamath Proof Explorer

Theorem List for Metamath Proof Explorer - 32701-32800   *Has distinct variable group(s)

Type	Label	Description
Statement
Theorem	mgcmnt1 32701	The lower adjoint 𝐹 of a Galois connection is monotonically increasing. (Contributed by Thierry Arnoux, 26-Apr-2024.)
⊢ 𝐴 = (Base‘𝑉)    &   ⊢ 𝐵 = (Base‘𝑊)    &   ⊢ ≤ = (le‘𝑉)    &   ⊢ ≲ = (le‘𝑊)    &   ⊢ 𝐻 = (𝑉MGalConn𝑊)    &   ⊢ (𝜑 → 𝑉 ∈ Proset )    &   ⊢ (𝜑 → 𝑊 ∈ Proset )    &   ⊢ (𝜑 → 𝐹𝐻𝐺)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐴)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐴)    &   ⊢ (𝜑 → 𝑋 ≤ 𝑌)    ⇒   ⊢ (𝜑 → (𝐹‘𝑋) ≲ (𝐹‘𝑌))
Theorem	mgcmnt2 32702	The upper adjoint 𝐺 of a Galois connection is monotonically increasing. (Contributed by Thierry Arnoux, 26-Apr-2024.)
⊢ 𝐴 = (Base‘𝑉)    &   ⊢ 𝐵 = (Base‘𝑊)    &   ⊢ ≤ = (le‘𝑉)    &   ⊢ ≲ = (le‘𝑊)    &   ⊢ 𝐻 = (𝑉MGalConn𝑊)    &   ⊢ (𝜑 → 𝑉 ∈ Proset )    &   ⊢ (𝜑 → 𝑊 ∈ Proset )    &   ⊢ (𝜑 → 𝐹𝐻𝐺)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑋 ≲ 𝑌)    ⇒   ⊢ (𝜑 → (𝐺‘𝑋) ≤ (𝐺‘𝑌))
Theorem	mgcmntco 32703*	A Galois connection like statement, for two functions with same range. (Contributed by Thierry Arnoux, 26-Apr-2024.)
⊢ 𝐴 = (Base‘𝑉)    &   ⊢ 𝐵 = (Base‘𝑊)    &   ⊢ ≤ = (le‘𝑉)    &   ⊢ ≲ = (le‘𝑊)    &   ⊢ 𝐻 = (𝑉MGalConn𝑊)    &   ⊢ (𝜑 → 𝑉 ∈ Proset )    &   ⊢ (𝜑 → 𝑊 ∈ Proset )    &   ⊢ (𝜑 → 𝐹𝐻𝐺)    &   ⊢ 𝐶 = (Base‘𝑋)    &   ⊢ < = (le‘𝑋)    &   ⊢ (𝜑 → 𝑋 ∈ Proset )    &   ⊢ (𝜑 → 𝐾 ∈ (𝑉Monot𝑋))    &   ⊢ (𝜑 → 𝐿 ∈ (𝑊Monot𝑋))    ⇒   ⊢ (𝜑 → (∀𝑥 ∈ 𝐴 (𝐾‘𝑥) < (𝐿‘(𝐹‘𝑥)) ↔ ∀𝑦 ∈ 𝐵 (𝐾‘(𝐺‘𝑦)) < (𝐿‘𝑦)))
Theorem	dfmgc2lem 32704*	Lemma for dfmgc2, backwards direction. (Contributed by Thierry Arnoux, 26-Apr-2024.)
⊢ 𝐴 = (Base‘𝑉)    &   ⊢ 𝐵 = (Base‘𝑊)    &   ⊢ ≤ = (le‘𝑉)    &   ⊢ ≲ = (le‘𝑊)    &   ⊢ 𝐻 = (𝑉MGalConn𝑊)    &   ⊢ (𝜑 → 𝑉 ∈ Proset )    &   ⊢ (𝜑 → 𝑊 ∈ Proset )    &   ⊢ (𝜑 → 𝐹:𝐴⟶𝐵)    &   ⊢ (𝜑 → 𝐺:𝐵⟶𝐴)    &   ⊢ (𝜑 → ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 (𝑥 ≤ 𝑦 → (𝐹‘𝑥) ≲ (𝐹‘𝑦)))    &   ⊢ (𝜑 → ∀𝑢 ∈ 𝐵 ∀𝑣 ∈ 𝐵 (𝑢 ≲ 𝑣 → (𝐺‘𝑢) ≤ (𝐺‘𝑣)))    &   ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑥 ≤ (𝐺‘(𝐹‘𝑥)))    &   ⊢ ((𝜑 ∧ 𝑢 ∈ 𝐵) → (𝐹‘(𝐺‘𝑢)) ≲ 𝑢)    ⇒   ⊢ (𝜑 → 𝐹𝐻𝐺)
Theorem	dfmgc2 32705*	Alternate definition of the monotone Galois connection. (Contributed by Thierry Arnoux, 26-Apr-2024.)
⊢ 𝐴 = (Base‘𝑉)    &   ⊢ 𝐵 = (Base‘𝑊)    &   ⊢ ≤ = (le‘𝑉)    &   ⊢ ≲ = (le‘𝑊)    &   ⊢ 𝐻 = (𝑉MGalConn𝑊)    &   ⊢ (𝜑 → 𝑉 ∈ Proset )    &   ⊢ (𝜑 → 𝑊 ∈ Proset )    ⇒   ⊢ (𝜑 → (𝐹𝐻𝐺 ↔ ((𝐹:𝐴⟶𝐵 ∧ 𝐺:𝐵⟶𝐴) ∧ ((∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 (𝑥 ≤ 𝑦 → (𝐹‘𝑥) ≲ (𝐹‘𝑦)) ∧ ∀𝑢 ∈ 𝐵 ∀𝑣 ∈ 𝐵 (𝑢 ≲ 𝑣 → (𝐺‘𝑢) ≤ (𝐺‘𝑣))) ∧ (∀𝑢 ∈ 𝐵 (𝐹‘(𝐺‘𝑢)) ≲ 𝑢 ∧ ∀𝑥 ∈ 𝐴 𝑥 ≤ (𝐺‘(𝐹‘𝑥)))))))
Theorem	mgcmnt1d 32706	Galois connection implies monotonicity of the left adjoint. (Contributed by Thierry Arnoux, 21-Jul-2024.)
⊢ 𝐻 = (𝑉MGalConn𝑊)    &   ⊢ (𝜑 → 𝑉 ∈ Proset )    &   ⊢ (𝜑 → 𝑊 ∈ Proset )    &   ⊢ (𝜑 → 𝐹𝐻𝐺)    ⇒   ⊢ (𝜑 → 𝐹 ∈ (𝑉Monot𝑊))
Theorem	mgcmnt2d 32707	Galois connection implies monotonicity of the right adjoint. (Contributed by Thierry Arnoux, 21-Jul-2024.)
⊢ 𝐻 = (𝑉MGalConn𝑊)    &   ⊢ (𝜑 → 𝑉 ∈ Proset )    &   ⊢ (𝜑 → 𝑊 ∈ Proset )    &   ⊢ (𝜑 → 𝐹𝐻𝐺)    ⇒   ⊢ (𝜑 → 𝐺 ∈ (𝑊Monot𝑉))
Theorem	mgccnv 32708	The inverse Galois connection is the Galois connection of the dual orders. (Contributed by Thierry Arnoux, 26-Apr-2024.)
⊢ 𝐻 = (𝑉MGalConn𝑊)    &   ⊢ 𝑀 = ((ODual‘𝑊)MGalConn(ODual‘𝑉))    ⇒   ⊢ ((𝑉 ∈ Proset ∧ 𝑊 ∈ Proset ) → (𝐹𝐻𝐺 ↔ 𝐺𝑀𝐹))
Theorem	pwrssmgc 32709*	Given a function 𝐹, exhibit a Galois connection between subsets of its domain and subsets of its range. (Contributed by Thierry Arnoux, 26-Apr-2024.)
⊢ 𝐺 = (𝑛 ∈ 𝒫 𝑌 ↦ (◡𝐹 “ 𝑛))    &   ⊢ 𝐻 = (𝑚 ∈ 𝒫 𝑋 ↦ {𝑦 ∈ 𝑌 ∣ (◡𝐹 “ {𝑦}) ⊆ 𝑚})    &   ⊢ 𝑉 = (toInc‘𝒫 𝑌)    &   ⊢ 𝑊 = (toInc‘𝒫 𝑋)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐴)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐹:𝑋⟶𝑌)    ⇒   ⊢ (𝜑 → 𝐺(𝑉MGalConn𝑊)𝐻)
Theorem	mgcf1olem1 32710	Property of a Galois connection, lemma for mgcf1o 32712. (Contributed by Thierry Arnoux, 26-Jul-2024.)
⊢ 𝐻 = (𝑉MGalConn𝑊)    &   ⊢ 𝐴 = (Base‘𝑉)    &   ⊢ 𝐵 = (Base‘𝑊)    &   ⊢ ≤ = (le‘𝑉)    &   ⊢ ≲ = (le‘𝑊)    &   ⊢ (𝜑 → 𝑉 ∈ Poset)    &   ⊢ (𝜑 → 𝑊 ∈ Poset)    &   ⊢ (𝜑 → 𝐹𝐻𝐺)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐴)    ⇒   ⊢ (𝜑 → (𝐹‘(𝐺‘(𝐹‘𝑋))) = (𝐹‘𝑋))
Theorem	mgcf1olem2 32711	Property of a Galois connection, lemma for mgcf1o 32712. (Contributed by Thierry Arnoux, 26-Jul-2024.)
⊢ 𝐻 = (𝑉MGalConn𝑊)    &   ⊢ 𝐴 = (Base‘𝑉)    &   ⊢ 𝐵 = (Base‘𝑊)    &   ⊢ ≤ = (le‘𝑉)    &   ⊢ ≲ = (le‘𝑊)    &   ⊢ (𝜑 → 𝑉 ∈ Poset)    &   ⊢ (𝜑 → 𝑊 ∈ Poset)    &   ⊢ (𝜑 → 𝐹𝐻𝐺)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    ⇒   ⊢ (𝜑 → (𝐺‘(𝐹‘(𝐺‘𝑌))) = (𝐺‘𝑌))
Theorem	mgcf1o 32712	Given a Galois connection, exhibit an order isomorphism. (Contributed by Thierry Arnoux, 26-Jul-2024.)
⊢ 𝐻 = (𝑉MGalConn𝑊)    &   ⊢ 𝐴 = (Base‘𝑉)    &   ⊢ 𝐵 = (Base‘𝑊)    &   ⊢ ≤ = (le‘𝑉)    &   ⊢ ≲ = (le‘𝑊)    &   ⊢ (𝜑 → 𝑉 ∈ Poset)    &   ⊢ (𝜑 → 𝑊 ∈ Poset)    &   ⊢ (𝜑 → 𝐹𝐻𝐺)    ⇒   ⊢ (𝜑 → (𝐹 ↾ ran 𝐺) Isom ≤ , ≲ (ran 𝐺, ran 𝐹))
21.3.8.6  Extended reals Structure - misc additions
Axiom	ax-xrssca 32713	Assume the scalar component of the extended real structure is the field of the real numbers (this has to be defined in the main body of set.mm). (Contributed by Thierry Arnoux, 22-Oct-2017.)
⊢ ℝfld = (Scalar‘ℝ*𝑠)
Axiom	ax-xrsvsca 32714	Assume the scalar product of the extended real structure is the extended real number multiplication operation (this has to be defined in the main body of set.mm). (Contributed by Thierry Arnoux, 22-Oct-2017.)
⊢ ·e = ( ·𝑠 ‘ℝ*𝑠)
Theorem	xrs0 32715	The zero of the extended real numbers. The extended real is not a group, as its addition is not associative. (cf. xaddass 13252 and df-xrs 17475), however it has a zero. (Contributed by Thierry Arnoux, 13-Jun-2017.)
⊢ 0 = (0g‘ℝ*𝑠)
Theorem	xrslt 32716	The "strictly less than" relation for the extended real structure. (Contributed by Thierry Arnoux, 30-Jan-2018.)
⊢ < = (lt‘ℝ*𝑠)
Theorem	xrsinvgval 32717	The inversion operation in the extended real numbers. The extended real is not a group, as its addition is not associative. (cf. xaddass 13252 and df-xrs 17475), however it has an inversion operation. (Contributed by Thierry Arnoux, 13-Jun-2017.)
⊢ (𝐵 ∈ ℝ* → ((invg‘ℝ*𝑠)‘𝐵) = -𝑒𝐵)
Theorem	xrsmulgzz 32718	The "multiple" function in the extended real numbers structure. (Contributed by Thierry Arnoux, 14-Jun-2017.)
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℝ*) → (𝐴(.g‘ℝ*𝑠)𝐵) = (𝐴 ·e 𝐵))
Theorem	xrstos 32719	The extended real numbers form a toset. (Contributed by Thierry Arnoux, 15-Feb-2018.)
⊢ ℝ*𝑠 ∈ Toset
Theorem	xrsclat 32720	The extended real numbers form a complete lattice. (Contributed by Thierry Arnoux, 15-Feb-2018.)
⊢ ℝ*𝑠 ∈ CLat
Theorem	xrsp0 32721	The poset 0 of the extended real numbers is minus infinity. (Contributed by Thierry Arnoux, 18-Feb-2018.) (Proof shortened by AV, 28-Sep-2020.)
⊢ -∞ = (0.‘ℝ*𝑠)
Theorem	xrsp1 32722	The poset 1 of the extended real numbers is plus infinity. (Contributed by Thierry Arnoux, 18-Feb-2018.)
⊢ +∞ = (1.‘ℝ*𝑠)
21.3.8.7  The extended nonnegative real numbers commutative monoid
Theorem	xrge0base 32723	The base of the extended nonnegative real numbers. (Contributed by Thierry Arnoux, 30-Jan-2017.)
⊢ (0[,]+∞) = (Base‘(ℝ*𝑠 ↾s (0[,]+∞)))
Theorem	xrge00 32724	The zero of the extended nonnegative real numbers monoid. (Contributed by Thierry Arnoux, 30-Jan-2017.)
⊢ 0 = (0g‘(ℝ*𝑠 ↾s (0[,]+∞)))
Theorem	xrge0plusg 32725	The additive law of the extended nonnegative real numbers monoid is the addition in the extended real numbers. (Contributed by Thierry Arnoux, 20-Mar-2017.)
⊢ +𝑒 = (+g‘(ℝ*𝑠 ↾s (0[,]+∞)))
Theorem	xrge0le 32726	The "less than or equal to" relation in the extended real numbers. (Contributed by Thierry Arnoux, 14-Mar-2018.)
⊢ ≤ = (le‘(ℝ*𝑠 ↾s (0[,]+∞)))
Theorem	xrge0mulgnn0 32727	The group multiple function in the extended nonnegative real numbers. (Contributed by Thierry Arnoux, 14-Jun-2017.)
⊢ ((𝐴 ∈ ℕ0 ∧ 𝐵 ∈ (0[,]+∞)) → (𝐴(.g‘(ℝ*𝑠 ↾s (0[,]+∞)))𝐵) = (𝐴 ·e 𝐵))
Theorem	xrge0addass 32728	Associativity of extended nonnegative real addition. (Contributed by Thierry Arnoux, 8-Jun-2017.)
⊢ ((𝐴 ∈ (0[,]+∞) ∧ 𝐵 ∈ (0[,]+∞) ∧ 𝐶 ∈ (0[,]+∞)) → ((𝐴 +𝑒 𝐵) +𝑒 𝐶) = (𝐴 +𝑒 (𝐵 +𝑒 𝐶)))
Theorem	xrge0addgt0 32729	The sum of nonnegative and positive numbers is positive. See addgtge0 11724. (Contributed by Thierry Arnoux, 6-Jul-2017.)
⊢ (((𝐴 ∈ (0[,]+∞) ∧ 𝐵 ∈ (0[,]+∞)) ∧ 0 < 𝐴) → 0 < (𝐴 +𝑒 𝐵))
Theorem	xrge0adddir 32730	Right-distributivity of extended nonnegative real multiplication over addition. (Contributed by Thierry Arnoux, 30-Jun-2017.)
⊢ ((𝐴 ∈ (0[,]+∞) ∧ 𝐵 ∈ (0[,]+∞) ∧ 𝐶 ∈ (0[,]+∞)) → ((𝐴 +𝑒 𝐵) ·e 𝐶) = ((𝐴 ·e 𝐶) +𝑒 (𝐵 ·e 𝐶)))
Theorem	xrge0adddi 32731	Left-distributivity of extended nonnegative real multiplication over addition. (Contributed by Thierry Arnoux, 6-Sep-2018.)
⊢ ((𝐴 ∈ (0[,]+∞) ∧ 𝐵 ∈ (0[,]+∞) ∧ 𝐶 ∈ (0[,]+∞)) → (𝐶 ·e (𝐴 +𝑒 𝐵)) = ((𝐶 ·e 𝐴) +𝑒 (𝐶 ·e 𝐵)))
Theorem	xrge0npcan 32732	Extended nonnegative real version of npcan 11491. (Contributed by Thierry Arnoux, 9-Jun-2017.)
⊢ ((𝐴 ∈ (0[,]+∞) ∧ 𝐵 ∈ (0[,]+∞) ∧ 𝐵 ≤ 𝐴) → ((𝐴 +𝑒 -𝑒𝐵) +𝑒 𝐵) = 𝐴)
Theorem	fsumrp0cl 32733*	Closure of a finite sum of nonnegative reals. (Contributed by Thierry Arnoux, 25-Jun-2017.)
⊢ (𝜑 → 𝐴 ∈ Fin)    &   ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝐵 ∈ (0[,)+∞))    ⇒   ⊢ (𝜑 → Σ𝑘 ∈ 𝐴 𝐵 ∈ (0[,)+∞))
21.3.9  Algebra
21.3.9.1  Monoids Homomorphisms
Theorem	abliso 32734	The image of an Abelian group by a group isomorphism is also Abelian. (Contributed by Thierry Arnoux, 8-Mar-2018.)
⊢ ((𝑀 ∈ Abel ∧ 𝐹 ∈ (𝑀 GrpIso 𝑁)) → 𝑁 ∈ Abel)
Theorem	lmhmghmd 32735	A module homomorphism is a group homomorphism. (Contributed by Thierry Arnoux, 2-Apr-2025.)
⊢ (𝜑 → 𝐹 ∈ (𝑆 LMHom 𝑇))    ⇒   ⊢ (𝜑 → 𝐹 ∈ (𝑆 GrpHom 𝑇))
Theorem	mhmimasplusg 32736	Value of the operation of the surjective image. (Contributed by Thierry Arnoux, 2-Apr-2025.)
⊢ 𝑊 = (𝐹 “s 𝑉)    &   ⊢ 𝐵 = (Base‘𝑉)    &   ⊢ 𝐶 = (Base‘𝑊)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐹:𝐵–onto→𝐶)    &   ⊢ (𝜑 → 𝐹 ∈ (𝑉 MndHom 𝑊))    &   ⊢ + = (+g‘𝑉)    &   ⊢ ⨣ = (+g‘𝑊)    ⇒   ⊢ (𝜑 → ((𝐹‘𝑋) ⨣ (𝐹‘𝑌)) = (𝐹‘(𝑋 + 𝑌)))
Theorem	lmhmimasvsca 32737	Value of the scalar product of the surjective image of a module. (Contributed by Thierry Arnoux, 2-Apr-2025.)
⊢ 𝑊 = (𝐹 “s 𝑉)    &   ⊢ 𝐵 = (Base‘𝑉)    &   ⊢ 𝐶 = (Base‘𝑊)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐹:𝐵–onto→𝐶)    &   ⊢ (𝜑 → 𝐹 ∈ (𝑉 LMHom 𝑊))    &   ⊢ · = ( ·𝑠 ‘𝑉)    &   ⊢ × = ( ·𝑠 ‘𝑊)    &   ⊢ 𝐾 = (Base‘(Scalar‘𝑉))    ⇒   ⊢ (𝜑 → (𝑋 × (𝐹‘𝑌)) = (𝐹‘(𝑋 · 𝑌)))
21.3.9.2  Finitely supported group sums - misc additions
Theorem	gsumsubg 32738	The group sum in a subgroup is the same as the group sum. (Contributed by Thierry Arnoux, 28-May-2023.)
⊢ 𝐻 = (𝐺 ↾s 𝐵)    &   ⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐹:𝐴⟶𝐵)    &   ⊢ (𝜑 → 𝐵 ∈ (SubGrp‘𝐺))    ⇒   ⊢ (𝜑 → (𝐺 Σg 𝐹) = (𝐻 Σg 𝐹))
Theorem	gsumsra 32739	The group sum in a subring algebra is the same as the ring's group sum. (Contributed by Thierry Arnoux, 28-May-2023.)
⊢ 𝐴 = ((subringAlg ‘𝑅)‘𝐵)    &   ⊢ (𝜑 → 𝐹 ∈ 𝑈)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐴 ∈ 𝑊)    &   ⊢ (𝜑 → 𝐵 ⊆ (Base‘𝑅))    ⇒   ⊢ (𝜑 → (𝑅 Σg 𝐹) = (𝐴 Σg 𝐹))
Theorem	gsummpt2co 32740*	Split a finite sum into a sum of a collection of sums over disjoint subsets. (Contributed by Thierry Arnoux, 27-Mar-2018.)
⊢ 𝐵 = (Base‘𝑊)    &   ⊢ 0 = (0g‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ CMnd)    &   ⊢ (𝜑 → 𝐴 ∈ Fin)    &   ⊢ (𝜑 → 𝐸 ∈ 𝑉)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐶 ∈ 𝐵)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐷 ∈ 𝐸)    &   ⊢ 𝐹 = (𝑥 ∈ 𝐴 ↦ 𝐷)    ⇒   ⊢ (𝜑 → (𝑊 Σg (𝑥 ∈ 𝐴 ↦ 𝐶)) = (𝑊 Σg (𝑦 ∈ 𝐸 ↦ (𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑦}) ↦ 𝐶)))))
Theorem	gsummpt2d 32741*	Express a finite sum over a two-dimensional range as a double sum. See also gsum2d 19918. (Contributed by Thierry Arnoux, 27-Apr-2020.)
⊢ Ⅎ𝑧𝐶    &   ⊢ Ⅎ𝑦𝜑    &   ⊢ 𝐵 = (Base‘𝑊)    &   ⊢ (𝑥 = ⟨𝑦, 𝑧⟩ → 𝐶 = 𝐷)    &   ⊢ (𝜑 → Rel 𝐴)    &   ⊢ (𝜑 → 𝐴 ∈ Fin)    &   ⊢ (𝜑 → 𝑊 ∈ CMnd)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐶 ∈ 𝐵)    ⇒   ⊢ (𝜑 → (𝑊 Σg (𝑥 ∈ 𝐴 ↦ 𝐶)) = (𝑊 Σg (𝑦 ∈ dom 𝐴 ↦ (𝑊 Σg (𝑧 ∈ (𝐴 “ {𝑦}) ↦ 𝐷)))))
Theorem	lmodvslmhm 32742*	Scalar multiplication in a left module by a fixed element is a group homomorphism. (Contributed by Thierry Arnoux, 12-Jun-2023.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐹 = (Scalar‘𝑊)    &   ⊢ · = ( ·𝑠 ‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐹)    ⇒   ⊢ ((𝑊 ∈ LMod ∧ 𝑌 ∈ 𝑉) → (𝑥 ∈ 𝐾 ↦ (𝑥 · 𝑌)) ∈ (𝐹 GrpHom 𝑊))
Theorem	gsumvsmul1 32743*	Pull a scalar multiplication out of a sum of vectors. This theorem properly generalizes gsummulc1 20241, since every ring is a left module over itself. (Contributed by Thierry Arnoux, 12-Jun-2023.)
⊢ 𝐵 = (Base‘𝑅)    &   ⊢ 𝑆 = (Scalar‘𝑅)    &   ⊢ 𝐾 = (Base‘𝑆)    &   ⊢ 0 = (0g‘𝑆)    &   ⊢ · = ( ·𝑠 ‘𝑅)    &   ⊢ (𝜑 → 𝑅 ∈ LMod)    &   ⊢ (𝜑 → 𝑆 ∈ CMnd)    &   ⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → (𝑘 ∈ 𝐴 ↦ 𝑋) finSupp 0 )    ⇒   ⊢ (𝜑 → (𝑅 Σg (𝑘 ∈ 𝐴 ↦ (𝑋 · 𝑌))) = ((𝑆 Σg (𝑘 ∈ 𝐴 ↦ 𝑋)) · 𝑌))
Theorem	gsummptres 32744*	Extend a finite group sum by padding outside with zeroes. Proof generated using OpenAI's proof assistant. (Contributed by Thierry Arnoux, 11-Jul-2020.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ 0 = (0g‘𝐺)    &   ⊢ (𝜑 → 𝐺 ∈ CMnd)    &   ⊢ (𝜑 → 𝐴 ∈ Fin)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐶 ∈ 𝐵)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ (𝐴 ∖ 𝐷)) → 𝐶 = 0 )    ⇒   ⊢ (𝜑 → (𝐺 Σg (𝑥 ∈ 𝐴 ↦ 𝐶)) = (𝐺 Σg (𝑥 ∈ (𝐴 ∩ 𝐷) ↦ 𝐶)))
Theorem	gsummptres2 32745*	Extend a finite group sum by padding outside with zeroes. (Contributed by Thierry Arnoux, 22-Jun-2024.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ 0 = (0g‘𝐺)    &   ⊢ (𝜑 → 𝐺 ∈ CMnd)    &   ⊢ (𝜑 → 𝐴 ∈ 𝑉)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ (𝐴 ∖ 𝑆)) → 𝑌 = 0 )    &   ⊢ (𝜑 → 𝑆 ∈ Fin)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑆 ⊆ 𝐴)    ⇒   ⊢ (𝜑 → (𝐺 Σg (𝑥 ∈ 𝐴 ↦ 𝑌)) = (𝐺 Σg (𝑥 ∈ 𝑆 ↦ 𝑌)))
Theorem	gsumzresunsn 32746	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 32747*	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	gsumhashmul 32748*	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	xrge0tsmsd 32749*	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 32750	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 32751	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))
21.3.9.3  Centralizers and centers - misc additions
Theorem	cntzun 32752	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 32753	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 32754	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)
21.3.9.4  Totally ordered monoids and groups
Syntax	comnd 32755	Extend class notation with the class of all right ordered monoids.
class oMnd
Syntax	cogrp 32756	Extend class notation with the class of all right ordered groups.
class oGrp
Definition	df-omnd 32757*	Define class of all right ordered monoids. An ordered monoid is a monoid with a total ordering compatible with its operation. It is possible to use this definition also for left ordered monoids, by applying it to (oppg‘𝑀). (Contributed by Thierry Arnoux, 13-Mar-2018.)
⊢ oMnd = {𝑔 ∈ Mnd ∣ [(Base‘𝑔) / 𝑣][(+g‘𝑔) / 𝑝][(le‘𝑔) / 𝑙](𝑔 ∈ Toset ∧ ∀𝑎 ∈ 𝑣 ∀𝑏 ∈ 𝑣 ∀𝑐 ∈ 𝑣 (𝑎𝑙𝑏 → (𝑎𝑝𝑐)𝑙(𝑏𝑝𝑐)))}
Definition	df-ogrp 32758	Define class of all ordered groups. An ordered group is a group with a total ordering compatible with its operation. (Contributed by Thierry Arnoux, 13-Mar-2018.)
⊢ oGrp = (Grp ∩ oMnd)
Theorem	isomnd 32759*	A (left) ordered monoid is a monoid with a total ordering compatible with its operation. (Contributed by Thierry Arnoux, 30-Jan-2018.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ + = (+g‘𝑀)    &   ⊢ ≤ = (le‘𝑀)    ⇒   ⊢ (𝑀 ∈ oMnd ↔ (𝑀 ∈ Mnd ∧ 𝑀 ∈ Toset ∧ ∀𝑎 ∈ 𝐵 ∀𝑏 ∈ 𝐵 ∀𝑐 ∈ 𝐵 (𝑎 ≤ 𝑏 → (𝑎 + 𝑐) ≤ (𝑏 + 𝑐))))
Theorem	isogrp 32760	A (left-)ordered group is a group with a total ordering compatible with its operations. (Contributed by Thierry Arnoux, 23-Mar-2018.)
⊢ (𝐺 ∈ oGrp ↔ (𝐺 ∈ Grp ∧ 𝐺 ∈ oMnd))
Theorem	ogrpgrp 32761	A left-ordered group is a group. (Contributed by Thierry Arnoux, 9-Jul-2018.)
⊢ (𝐺 ∈ oGrp → 𝐺 ∈ Grp)
Theorem	omndmnd 32762	A left-ordered monoid is a monoid. (Contributed by Thierry Arnoux, 13-Mar-2018.)
⊢ (𝑀 ∈ oMnd → 𝑀 ∈ Mnd)
Theorem	omndtos 32763	A left-ordered monoid is a totally ordered set. (Contributed by Thierry Arnoux, 13-Mar-2018.)
⊢ (𝑀 ∈ oMnd → 𝑀 ∈ Toset)
Theorem	omndadd 32764	In an ordered monoid, the ordering is compatible with group addition. (Contributed by Thierry Arnoux, 30-Jan-2018.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ ≤ = (le‘𝑀)    &   ⊢ + = (+g‘𝑀)    ⇒   ⊢ ((𝑀 ∈ oMnd ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) ∧ 𝑋 ≤ 𝑌) → (𝑋 + 𝑍) ≤ (𝑌 + 𝑍))
Theorem	omndaddr 32765	In a right ordered monoid, the ordering is compatible with group addition. (Contributed by Thierry Arnoux, 30-Jan-2018.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ ≤ = (le‘𝑀)    &   ⊢ + = (+g‘𝑀)    ⇒   ⊢ (((oppg‘𝑀) ∈ oMnd ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) ∧ 𝑋 ≤ 𝑌) → (𝑍 + 𝑋) ≤ (𝑍 + 𝑌))
Theorem	omndadd2d 32766	In a commutative left ordered monoid, the ordering is compatible with monoid addition. Double addition version. (Contributed by Thierry Arnoux, 30-Jan-2018.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ ≤ = (le‘𝑀)    &   ⊢ + = (+g‘𝑀)    &   ⊢ (𝜑 → 𝑀 ∈ oMnd)    &   ⊢ (𝜑 → 𝑊 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑍 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑋 ≤ 𝑍)    &   ⊢ (𝜑 → 𝑌 ≤ 𝑊)    &   ⊢ (𝜑 → 𝑀 ∈ CMnd)    ⇒   ⊢ (𝜑 → (𝑋 + 𝑌) ≤ (𝑍 + 𝑊))
Theorem	omndadd2rd 32767	In a left- and right- ordered monoid, the ordering is compatible with monoid addition. Double addition version. (Contributed by Thierry Arnoux, 2-May-2018.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ ≤ = (le‘𝑀)    &   ⊢ + = (+g‘𝑀)    &   ⊢ (𝜑 → 𝑀 ∈ oMnd)    &   ⊢ (𝜑 → 𝑊 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑍 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑋 ≤ 𝑍)    &   ⊢ (𝜑 → 𝑌 ≤ 𝑊)    &   ⊢ (𝜑 → (oppg‘𝑀) ∈ oMnd)    ⇒   ⊢ (𝜑 → (𝑋 + 𝑌) ≤ (𝑍 + 𝑊))
Theorem	submomnd 32768	A submonoid of an ordered monoid is also ordered. (Contributed by Thierry Arnoux, 23-Mar-2018.)
⊢ ((𝑀 ∈ oMnd ∧ (𝑀 ↾s 𝐴) ∈ Mnd) → (𝑀 ↾s 𝐴) ∈ oMnd)
Theorem	xrge0omnd 32769	The nonnegative extended real numbers form an ordered monoid. (Contributed by Thierry Arnoux, 22-Mar-2018.)
⊢ (ℝ*𝑠 ↾s (0[,]+∞)) ∈ oMnd
Theorem	omndmul2 32770	In an ordered monoid, the ordering is compatible with group power. This version does not require the monoid to be commutative. (Contributed by Thierry Arnoux, 23-Mar-2018.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ ≤ = (le‘𝑀)    &   ⊢ · = (.g‘𝑀)    &   ⊢ 0 = (0g‘𝑀)    ⇒   ⊢ ((𝑀 ∈ oMnd ∧ (𝑋 ∈ 𝐵 ∧ 𝑁 ∈ ℕ0) ∧ 0 ≤ 𝑋) → 0 ≤ (𝑁 · 𝑋))
Theorem	omndmul3 32771	In an ordered monoid, the ordering is compatible with group power. This version does not require the monoid to be commutative. (Contributed by Thierry Arnoux, 23-Mar-2018.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ ≤ = (le‘𝑀)    &   ⊢ · = (.g‘𝑀)    &   ⊢ 0 = (0g‘𝑀)    &   ⊢ (𝜑 → 𝑀 ∈ oMnd)    &   ⊢ (𝜑 → 𝑁 ∈ ℕ0)    &   ⊢ (𝜑 → 𝑃 ∈ ℕ0)    &   ⊢ (𝜑 → 𝑁 ≤ 𝑃)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐵)    &   ⊢ (𝜑 → 0 ≤ 𝑋)    ⇒   ⊢ (𝜑 → (𝑁 · 𝑋) ≤ (𝑃 · 𝑋))
Theorem	omndmul 32772	In a commutative ordered monoid, the ordering is compatible with group power. (Contributed by Thierry Arnoux, 30-Jan-2018.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ ≤ = (le‘𝑀)    &   ⊢ · = (.g‘𝑀)    &   ⊢ (𝜑 → 𝑀 ∈ oMnd)    &   ⊢ (𝜑 → 𝑀 ∈ CMnd)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑁 ∈ ℕ0)    &   ⊢ (𝜑 → 𝑋 ≤ 𝑌)    ⇒   ⊢ (𝜑 → (𝑁 · 𝑋) ≤ (𝑁 · 𝑌))
Theorem	ogrpinv0le 32773	In an ordered group, the ordering is compatible with group inverse. (Contributed by Thierry Arnoux, 3-Sep-2018.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ ≤ = (le‘𝐺)    &   ⊢ 𝐼 = (invg‘𝐺)    &   ⊢ 0 = (0g‘𝐺)    ⇒   ⊢ ((𝐺 ∈ oGrp ∧ 𝑋 ∈ 𝐵) → ( 0 ≤ 𝑋 ↔ (𝐼‘𝑋) ≤ 0 ))
Theorem	ogrpsub 32774	In an ordered group, the ordering is compatible with group subtraction. (Contributed by Thierry Arnoux, 30-Jan-2018.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ ≤ = (le‘𝐺)    &   ⊢ − = (-g‘𝐺)    ⇒   ⊢ ((𝐺 ∈ oGrp ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) ∧ 𝑋 ≤ 𝑌) → (𝑋 − 𝑍) ≤ (𝑌 − 𝑍))
Theorem	ogrpaddlt 32775	In an ordered group, strict ordering is compatible with group addition. (Contributed by Thierry Arnoux, 20-Jan-2018.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ < = (lt‘𝐺)    &   ⊢ + = (+g‘𝐺)    ⇒   ⊢ ((𝐺 ∈ oGrp ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) ∧ 𝑋 < 𝑌) → (𝑋 + 𝑍) < (𝑌 + 𝑍))
Theorem	ogrpaddltbi 32776	In a right ordered group, strict ordering is compatible with group addition. (Contributed by Thierry Arnoux, 3-Sep-2018.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ < = (lt‘𝐺)    &   ⊢ + = (+g‘𝐺)    ⇒   ⊢ ((𝐺 ∈ oGrp ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵)) → (𝑋 < 𝑌 ↔ (𝑋 + 𝑍) < (𝑌 + 𝑍)))
Theorem	ogrpaddltrd 32777	In a right ordered group, strict ordering is compatible with group addition. (Contributed by Thierry Arnoux, 3-Sep-2018.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ < = (lt‘𝐺)    &   ⊢ + = (+g‘𝐺)    &   ⊢ (𝜑 → 𝐺 ∈ 𝑉)    &   ⊢ (𝜑 → (oppg‘𝐺) ∈ oGrp)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑍 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑋 < 𝑌)    ⇒   ⊢ (𝜑 → (𝑍 + 𝑋) < (𝑍 + 𝑌))
Theorem	ogrpaddltrbid 32778	In a right ordered group, strict ordering is compatible with group addition. (Contributed by Thierry Arnoux, 4-Sep-2018.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ < = (lt‘𝐺)    &   ⊢ + = (+g‘𝐺)    &   ⊢ (𝜑 → 𝐺 ∈ 𝑉)    &   ⊢ (𝜑 → (oppg‘𝐺) ∈ oGrp)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐵)    &   ⊢ (𝜑 → 𝑍 ∈ 𝐵)    ⇒   ⊢ (𝜑 → (𝑋 < 𝑌 ↔ (𝑍 + 𝑋) < (𝑍 + 𝑌)))
Theorem	ogrpsublt 32779	In an ordered group, strict ordering is compatible with group addition. (Contributed by Thierry Arnoux, 3-Sep-2018.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ < = (lt‘𝐺)    &   ⊢ − = (-g‘𝐺)    ⇒   ⊢ ((𝐺 ∈ oGrp ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) ∧ 𝑋 < 𝑌) → (𝑋 − 𝑍) < (𝑌 − 𝑍))
Theorem	ogrpinv0lt 32780	In an ordered group, the ordering is compatible with group inverse. (Contributed by Thierry Arnoux, 3-Sep-2018.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ < = (lt‘𝐺)    &   ⊢ 𝐼 = (invg‘𝐺)    &   ⊢ 0 = (0g‘𝐺)    ⇒   ⊢ ((𝐺 ∈ oGrp ∧ 𝑋 ∈ 𝐵) → ( 0 < 𝑋 ↔ (𝐼‘𝑋) < 0 ))
Theorem	ogrpinvlt 32781	In an ordered group, the ordering is compatible with group inverse. (Contributed by Thierry Arnoux, 3-Sep-2018.)
⊢ 𝐵 = (Base‘𝐺)    &   ⊢ < = (lt‘𝐺)    &   ⊢ 𝐼 = (invg‘𝐺)    ⇒   ⊢ (((𝐺 ∈ oGrp ∧ (oppg‘𝐺) ∈ oGrp) ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → (𝑋 < 𝑌 ↔ (𝐼‘𝑌) < (𝐼‘𝑋)))
Theorem	gsumle 32782	A finite sum in an ordered monoid is monotonic. This proof would be much easier in an ordered group, where an inverse element would be available. (Contributed by Thierry Arnoux, 13-Mar-2018.)
⊢ 𝐵 = (Base‘𝑀)    &   ⊢ ≤ = (le‘𝑀)    &   ⊢ (𝜑 → 𝑀 ∈ oMnd)    &   ⊢ (𝜑 → 𝑀 ∈ CMnd)    &   ⊢ (𝜑 → 𝐴 ∈ Fin)    &   ⊢ (𝜑 → 𝐹:𝐴⟶𝐵)    &   ⊢ (𝜑 → 𝐺:𝐴⟶𝐵)    &   ⊢ (𝜑 → 𝐹 ∘r ≤ 𝐺)    ⇒   ⊢ (𝜑 → (𝑀 Σg 𝐹) ≤ (𝑀 Σg 𝐺))
21.3.9.5  The symmetric group
Theorem	symgfcoeu 32783*	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 32784	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 32785	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 32786*	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 32787	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 32788	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 32789	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 32790	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 32791	Variation on pmtrcnel 32790. (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 32792	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})))
21.3.9.6  Transpositions
Theorem	pmtridf1o 32793	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 32794	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 32795	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)
21.3.9.7  Permutation Signs
Theorem	psgnid 32796	Permutation sign of the identity. (Contributed by Thierry Arnoux, 21-Aug-2020.)
⊢ 𝑆 = (pmSgn‘𝐷)    ⇒   ⊢ (𝐷 ∈ Fin → (𝑆‘( I ↾ 𝐷)) = 1)
Theorem	psgndmfi 32797	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 32798	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 32799*	Lemma for psgnfzto1st 32804. 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 32800*	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)