P. 171 of Theorem List - Metamath Proof Explorer

Theorem List for Metamath Proof Explorer - 17001-17100   *Has distinct variable group(s)

Type	Label	Description
Statement
Theorem	pleid 17001	Utility theorem: self-referencing, index-independent form of df-ple 16908. (Contributed by NM, 9-Nov-2012.) (Revised by AV, 9-Sep-2021.)
⊢ le = Slot (le‘ndx)
Theorem	plendxnn 17002	The index value of the order slot is a positive integer. This property should be ensured for every concrete coding because otherwise it could not be used in an extensible structure (slots must be positive integers). (Contributed by AV, 30-Oct-2024.)
⊢ (le‘ndx) ∈ ℕ
Theorem	basendxltplendx 17003	The index value of the Base slot is less than the index value of the le slot. (Contributed by AV, 30-Oct-2024.)
⊢ (Base‘ndx) < (le‘ndx)
Theorem	plendxnbasendx 17004	The slot for the order is not the slot for the base set in an extensible structure. (Contributed by AV, 21-Oct-2024.) (Proof shortened by AV, 30-Oct-2024.)
⊢ (le‘ndx) ≠ (Base‘ndx)
Theorem	plendxnplusgndx 17005	The slot for the "less than or equal to" ordering is not the slot for the group operation in an extensible structure. Formerly part of proof for oppgle 31140. (Contributed by AV, 18-Oct-2024.)
⊢ (le‘ndx) ≠ (+g‘ndx)
Theorem	plendxnmulrndx 17006	The slot for the "less than or equal to" ordering is not the slot for the ring multiplication operation in an extensible structure. Formerly part of proof for opsrmulr 21166. (Contributed by AV, 1-Nov-2024.)
⊢ (le‘ndx) ≠ (.r‘ndx)
Theorem	plendxnscandx 17007	The slot for the "less than or equal to" ordering is not the slot for the scalar in an extensible structure. Formerly part of proof for opsrsca 21170. (Contributed by AV, 1-Nov-2024.)
⊢ (le‘ndx) ≠ (Scalar‘ndx)
Theorem	plendxnvscandx 17008	The slot for the "less than or equal to" ordering is not the slot for the scalar product in an extensible structure. Formerly part of proof for opsrvsca 21168. (Contributed by AV, 1-Nov-2024.)
⊢ (le‘ndx) ≠ ( ·𝑠 ‘ndx)
Theorem	otpsstr 17009	Functionality of a topological ordered space. (Contributed by Mario Carneiro, 12-Nov-2015.) (Revised by AV, 9-Sep-2021.)
⊢ 𝐾 = {⟨(Base‘ndx), 𝐵⟩, ⟨(TopSet‘ndx), 𝐽⟩, ⟨(le‘ndx), ≤ ⟩}    ⇒   ⊢ 𝐾 Struct ⟨1, ;10⟩
Theorem	otpsbas 17010	The base set of a topological ordered space. (Contributed by Mario Carneiro, 12-Nov-2015.) (Revised by AV, 9-Sep-2021.)
⊢ 𝐾 = {⟨(Base‘ndx), 𝐵⟩, ⟨(TopSet‘ndx), 𝐽⟩, ⟨(le‘ndx), ≤ ⟩}    ⇒   ⊢ (𝐵 ∈ 𝑉 → 𝐵 = (Base‘𝐾))
Theorem	otpstset 17011	The open sets of a topological ordered space. (Contributed by Mario Carneiro, 12-Nov-2015.) (Revised by AV, 9-Sep-2021.)
⊢ 𝐾 = {⟨(Base‘ndx), 𝐵⟩, ⟨(TopSet‘ndx), 𝐽⟩, ⟨(le‘ndx), ≤ ⟩}    ⇒   ⊢ (𝐽 ∈ 𝑉 → 𝐽 = (TopSet‘𝐾))
Theorem	otpsle 17012	The order of a topological ordered space. (Contributed by Mario Carneiro, 12-Nov-2015.) (Revised by AV, 9-Sep-2021.)
⊢ 𝐾 = {⟨(Base‘ndx), 𝐵⟩, ⟨(TopSet‘ndx), 𝐽⟩, ⟨(le‘ndx), ≤ ⟩}    ⇒   ⊢ ( ≤ ∈ 𝑉 → ≤ = (le‘𝐾))
Theorem	ressle 17013	le is unaffected by restriction. (Contributed by Mario Carneiro, 3-Nov-2015.)
⊢ 𝑊 = (𝐾 ↾s 𝐴)    &   ⊢ ≤ = (le‘𝐾)    ⇒   ⊢ (𝐴 ∈ 𝑉 → ≤ = (le‘𝑊))
Theorem	ocndx 17014	Index value of the df-ocomp 16909 slot. (Contributed by Mario Carneiro, 25-Oct-2015.)
⊢ (oc‘ndx) = ;11
Theorem	ocid 17015	Utility theorem: index-independent form of df-ocomp 16909. (Contributed by Mario Carneiro, 25-Oct-2015.)
⊢ oc = Slot (oc‘ndx)
Theorem	dsndx 17016	Index value of the df-ds 16910 slot. (Contributed by Mario Carneiro, 14-Aug-2015.)
⊢ (dist‘ndx) = ;12
Theorem	dsid 17017	Utility theorem: index-independent form of df-ds 16910. (Contributed by Mario Carneiro, 23-Dec-2013.)
⊢ dist = Slot (dist‘ndx)
Theorem	dsndxnn 17018	The index of the slot for the distance in an extensible structure is a positive integer. Formerly part of proof for tmslem 23543. (Contributed by AV, 28-Oct-2024.)
⊢ (dist‘ndx) ∈ ℕ
Theorem	basendxltdsndx 17019	The index of the slot for the base set is less then the index of the slot for the distance in an extensible structure. Formerly part of proof for tmslem 23543. (Contributed by AV, 28-Oct-2024.)
⊢ (Base‘ndx) < (dist‘ndx)
Theorem	dsndxnbasendx 17020	The slot for the distance is not the slot for the base set in an extensible structure. (Contributed by AV, 21-Oct-2024.) (Proof shortened by AV, 28-Oct-2024.)
⊢ (dist‘ndx) ≠ (Base‘ndx)
Theorem	dsndxnplusgndx 17021	The slot for the distance function is not the slot for the group operation in an extensible structure. Formerly part of proof for mgpds 19648. (Contributed by AV, 18-Oct-2024.)
⊢ (dist‘ndx) ≠ (+g‘ndx)
Theorem	dsndxnmulrndx 17022	The slot for the distance function is not the slot for the ring multiplication operation in an extensible structure. (Contributed by AV, 31-Oct-2024.)
⊢ (dist‘ndx) ≠ (.r‘ndx)
Theorem	slotsdnscsi 17023	The slots Scalar, ·𝑠 and ·𝑖 are different from the slot dist. Formerly part of sralem 20354 and proofs using it. (Contributed by AV, 29-Oct-2024.)
⊢ ((dist‘ndx) ≠ (Scalar‘ndx) ∧ (dist‘ndx) ≠ ( ·𝑠 ‘ndx) ∧ (dist‘ndx) ≠ (·𝑖‘ndx))
Theorem	dsndxntsetndx 17024	The slot for the distance function is not the slot for the topology in an extensible structure. Formerly part of proof for tngds 23717. (Contributed by AV, 29-Oct-2024.)
⊢ (dist‘ndx) ≠ (TopSet‘ndx)
Theorem	unifndx 17025	Index value of the df-unif 16911 slot. (Contributed by Thierry Arnoux, 17-Dec-2017.)
⊢ (UnifSet‘ndx) = ;13
Theorem	unifid 17026	Utility theorem: index-independent form of df-unif 16911. (Contributed by Thierry Arnoux, 17-Dec-2017.)
⊢ UnifSet = Slot (UnifSet‘ndx)
Theorem	unifndxnn 17027	The index of the slot for the uniform set in an extensible structure is a positive integer. Formerly part of proof for tuslem 23326. (Contributed by AV, 28-Oct-2024.)
⊢ (UnifSet‘ndx) ∈ ℕ
Theorem	basendxltunifndx 17028	The index of the slot for the base set is less then the index of the slot for the uniform set in an extensible structure. Formerly part of proof for tuslem 23326. (Contributed by AV, 28-Oct-2024.)
⊢ (Base‘ndx) < (UnifSet‘ndx)
Theorem	unifndxnbasendx 17029	The slot for the uniform set is not the slot for the base set in an extensible structure. (Contributed by AV, 21-Oct-2024.)
⊢ (UnifSet‘ndx) ≠ (Base‘ndx)
Theorem	unifndxntsetndx 17030	The slot for the uniform set is not the slot for the topology in an extensible structure. Formerly part of proof for tuslem 23326. (Contributed by AV, 28-Oct-2024.)
⊢ (UnifSet‘ndx) ≠ (TopSet‘ndx)
Theorem	ressunif 17031	UnifSet is unaffected by restriction. (Contributed by Thierry Arnoux, 7-Dec-2017.)
⊢ 𝐻 = (𝐺 ↾s 𝐴)    &   ⊢ 𝑈 = (UnifSet‘𝐺)    ⇒   ⊢ (𝐴 ∈ 𝑉 → 𝑈 = (UnifSet‘𝐻))
Theorem	odrngstr 17032	Functionality of an ordered metric ring. (Contributed by Mario Carneiro, 20-Aug-2015.) (Proof shortened by AV, 15-Sep-2021.)
⊢ 𝑊 = ({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), · ⟩} ∪ {⟨(TopSet‘ndx), 𝐽⟩, ⟨(le‘ndx), ≤ ⟩, ⟨(dist‘ndx), 𝐷⟩})    ⇒   ⊢ 𝑊 Struct ⟨1, ;12⟩
Theorem	odrngbas 17033	The base set of an ordered metric ring. (Contributed by Mario Carneiro, 20-Aug-2015.)
⊢ 𝑊 = ({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), · ⟩} ∪ {⟨(TopSet‘ndx), 𝐽⟩, ⟨(le‘ndx), ≤ ⟩, ⟨(dist‘ndx), 𝐷⟩})    ⇒   ⊢ (𝐵 ∈ 𝑉 → 𝐵 = (Base‘𝑊))
Theorem	odrngplusg 17034	The addition operation of an ordered metric ring. (Contributed by Mario Carneiro, 20-Aug-2015.)
⊢ 𝑊 = ({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), · ⟩} ∪ {⟨(TopSet‘ndx), 𝐽⟩, ⟨(le‘ndx), ≤ ⟩, ⟨(dist‘ndx), 𝐷⟩})    ⇒   ⊢ ( + ∈ 𝑉 → + = (+g‘𝑊))
Theorem	odrngmulr 17035	The multiplication operation of an ordered metric ring. (Contributed by Mario Carneiro, 20-Aug-2015.)
⊢ 𝑊 = ({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), · ⟩} ∪ {⟨(TopSet‘ndx), 𝐽⟩, ⟨(le‘ndx), ≤ ⟩, ⟨(dist‘ndx), 𝐷⟩})    ⇒   ⊢ ( · ∈ 𝑉 → · = (.r‘𝑊))
Theorem	odrngtset 17036	The open sets of an ordered metric ring. (Contributed by Mario Carneiro, 20-Aug-2015.)
⊢ 𝑊 = ({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), · ⟩} ∪ {⟨(TopSet‘ndx), 𝐽⟩, ⟨(le‘ndx), ≤ ⟩, ⟨(dist‘ndx), 𝐷⟩})    ⇒   ⊢ (𝐽 ∈ 𝑉 → 𝐽 = (TopSet‘𝑊))
Theorem	odrngle 17037	The order of an ordered metric ring. (Contributed by Mario Carneiro, 20-Aug-2015.)
⊢ 𝑊 = ({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), · ⟩} ∪ {⟨(TopSet‘ndx), 𝐽⟩, ⟨(le‘ndx), ≤ ⟩, ⟨(dist‘ndx), 𝐷⟩})    ⇒   ⊢ ( ≤ ∈ 𝑉 → ≤ = (le‘𝑊))
Theorem	odrngds 17038	The metric of an ordered metric ring. (Contributed by Mario Carneiro, 20-Aug-2015.)
⊢ 𝑊 = ({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), · ⟩} ∪ {⟨(TopSet‘ndx), 𝐽⟩, ⟨(le‘ndx), ≤ ⟩, ⟨(dist‘ndx), 𝐷⟩})    ⇒   ⊢ (𝐷 ∈ 𝑉 → 𝐷 = (dist‘𝑊))
Theorem	ressds 17039	dist is unaffected by restriction. (Contributed by Mario Carneiro, 26-Aug-2015.)
⊢ 𝐻 = (𝐺 ↾s 𝐴)    &   ⊢ 𝐷 = (dist‘𝐺)    ⇒   ⊢ (𝐴 ∈ 𝑉 → 𝐷 = (dist‘𝐻))
Theorem	homndx 17040	Index value of the df-hom 16912 slot. (Contributed by Mario Carneiro, 7-Jan-2017.)
⊢ (Hom ‘ndx) = ;14
Theorem	homid 17041	Utility theorem: index-independent form of df-hom 16912. (Contributed by Mario Carneiro, 7-Jan-2017.)
⊢ Hom = Slot (Hom ‘ndx)
Theorem	ccondx 17042	Index value of the df-cco 16913 slot. (Contributed by Mario Carneiro, 7-Jan-2017.)
⊢ (comp‘ndx) = ;15
Theorem	ccoid 17043	Utility theorem: index-independent form of df-cco 16913. (Contributed by Mario Carneiro, 7-Jan-2017.)
⊢ comp = Slot (comp‘ndx)
Theorem	slotsbhcdif 17044	The slots Base, Hom and comp are different. (Contributed by AV, 5-Mar-2020.) (Proof shortened by AV, 28-Oct-2024.)
⊢ ((Base‘ndx) ≠ (Hom ‘ndx) ∧ (Base‘ndx) ≠ (comp‘ndx) ∧ (Hom ‘ndx) ≠ (comp‘ndx))
Theorem	slotsbhcdifOLD 17045	Obsolete proof of slotsbhcdif 17044 as of 28-Oct-2024. The slots Base, Hom and comp are different. (Contributed by AV, 5-Mar-2020.) (Proof modification is discouraged.) (New usage is discouraged.)
⊢ ((Base‘ndx) ≠ (Hom ‘ndx) ∧ (Base‘ndx) ≠ (comp‘ndx) ∧ (Hom ‘ndx) ≠ (comp‘ndx))
Theorem	resshom 17046	Hom is unaffected by restriction. (Contributed by Mario Carneiro, 5-Jan-2017.)
⊢ 𝐷 = (𝐶 ↾s 𝐴)    &   ⊢ 𝐻 = (Hom ‘𝐶)    ⇒   ⊢ (𝐴 ∈ 𝑉 → 𝐻 = (Hom ‘𝐷))
Theorem	ressco 17047	comp is unaffected by restriction. (Contributed by Mario Carneiro, 5-Jan-2017.)
⊢ 𝐷 = (𝐶 ↾s 𝐴)    &   ⊢ · = (comp‘𝐶)    ⇒   ⊢ (𝐴 ∈ 𝑉 → · = (comp‘𝐷))
7.1.3  Definition of the structure product
Syntax	crest 17048	Extend class notation with the function returning a subspace topology.
class ↾t
Syntax	ctopn 17049	Extend class notation with the topology extractor function.
class TopOpen
Definition	df-rest 17050*	Function returning the subspace topology induced by the topology 𝑦 and the set 𝑥. (Contributed by FL, 20-Sep-2010.) (Revised by Mario Carneiro, 1-May-2015.)
⊢ ↾t = (𝑗 ∈ V, 𝑥 ∈ V ↦ ran (𝑦 ∈ 𝑗 ↦ (𝑦 ∩ 𝑥)))
Definition	df-topn 17051	Define the topology extractor function. This differs from df-tset 16907 when a structure has been restricted using df-ress 16868; in this case the TopSet component will still have a topology over the larger set, and this function fixes this by restricting the topology as well. (Contributed by Mario Carneiro, 13-Aug-2015.)
⊢ TopOpen = (𝑤 ∈ V ↦ ((TopSet‘𝑤) ↾t (Base‘𝑤)))
Theorem	restfn 17052	The subspace topology operator is a function on pairs. (Contributed by Mario Carneiro, 1-May-2015.)
⊢ ↾t Fn (V × V)
Theorem	topnfn 17053	The topology extractor function is a function on the universe. (Contributed by Mario Carneiro, 13-Aug-2015.)
⊢ TopOpen Fn V
Theorem	restval 17054*	The subspace topology induced by the topology 𝐽 on the set 𝐴. (Contributed by FL, 20-Sep-2010.) (Revised by Mario Carneiro, 1-May-2015.)
⊢ ((𝐽 ∈ 𝑉 ∧ 𝐴 ∈ 𝑊) → (𝐽 ↾t 𝐴) = ran (𝑥 ∈ 𝐽 ↦ (𝑥 ∩ 𝐴)))
Theorem	elrest 17055*	The predicate "is an open set of a subspace topology". (Contributed by FL, 5-Jan-2009.) (Revised by Mario Carneiro, 15-Dec-2013.)
⊢ ((𝐽 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 ∈ (𝐽 ↾t 𝐵) ↔ ∃𝑥 ∈ 𝐽 𝐴 = (𝑥 ∩ 𝐵)))
Theorem	elrestr 17056	Sufficient condition for being an open set in a subspace. (Contributed by Jeff Hankins, 11-Jul-2009.) (Revised by Mario Carneiro, 15-Dec-2013.)
⊢ ((𝐽 ∈ 𝑉 ∧ 𝑆 ∈ 𝑊 ∧ 𝐴 ∈ 𝐽) → (𝐴 ∩ 𝑆) ∈ (𝐽 ↾t 𝑆))
Theorem	0rest 17057	Value of the structure restriction when the topology input is empty. (Contributed by Mario Carneiro, 13-Aug-2015.)
⊢ (∅ ↾t 𝐴) = ∅
Theorem	restid2 17058	The subspace topology over a subset of the base set is the original topology. (Contributed by Mario Carneiro, 13-Aug-2015.)
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐽 ⊆ 𝒫 𝐴) → (𝐽 ↾t 𝐴) = 𝐽)
Theorem	restsspw 17059	The subspace topology is a collection of subsets of the restriction set. (Contributed by Mario Carneiro, 13-Aug-2015.)
⊢ (𝐽 ↾t 𝐴) ⊆ 𝒫 𝐴
Theorem	firest 17060	The finite intersections operator commutes with restriction. (Contributed by Mario Carneiro, 30-Aug-2015.)
⊢ (fi‘(𝐽 ↾t 𝐴)) = ((fi‘𝐽) ↾t 𝐴)
Theorem	restid 17061	The subspace topology of the base set is the original topology. (Contributed by Jeff Hankins, 9-Jul-2009.) (Revised by Mario Carneiro, 13-Aug-2015.)
⊢ 𝑋 = ∪ 𝐽    ⇒   ⊢ (𝐽 ∈ 𝑉 → (𝐽 ↾t 𝑋) = 𝐽)
Theorem	topnval 17062	Value of the topology extractor function. (Contributed by Mario Carneiro, 13-Aug-2015.)
⊢ 𝐵 = (Base‘𝑊)    &   ⊢ 𝐽 = (TopSet‘𝑊)    ⇒   ⊢ (𝐽 ↾t 𝐵) = (TopOpen‘𝑊)
Theorem	topnid 17063	Value of the topology extractor function when the topology is defined over the same set as the base. (Contributed by Mario Carneiro, 13-Aug-2015.)
⊢ 𝐵 = (Base‘𝑊)    &   ⊢ 𝐽 = (TopSet‘𝑊)    ⇒   ⊢ (𝐽 ⊆ 𝒫 𝐵 → 𝐽 = (TopOpen‘𝑊))
Theorem	topnpropd 17064	The topology extractor function depends only on the base and topology components. (Contributed by NM, 18-Jul-2006.)
⊢ (𝜑 → (Base‘𝐾) = (Base‘𝐿))    &   ⊢ (𝜑 → (TopSet‘𝐾) = (TopSet‘𝐿))    ⇒   ⊢ (𝜑 → (TopOpen‘𝐾) = (TopOpen‘𝐿))
Syntax	ctg 17065	Extend class notation with a function that converts a basis to its corresponding topology.
class topGen
Syntax	cpt 17066	Extend class notation with a function whose value is a product topology.
class ∏t
Syntax	c0g 17067	Extend class notation with group identity element.
class 0g
Syntax	cgsu 17068	Extend class notation to include finitely supported group sums.
class Σg
Definition	df-0g 17069*	Define group identity element. Remark: this definition is required here because the symbol 0g is already used in df-gsum 17070. The related theorems are provided later, see grpidval 18260. (Contributed by NM, 20-Aug-2011.)
⊢ 0g = (𝑔 ∈ V ↦ (℩𝑒(𝑒 ∈ (Base‘𝑔) ∧ ∀𝑥 ∈ (Base‘𝑔)((𝑒(+g‘𝑔)𝑥) = 𝑥 ∧ (𝑥(+g‘𝑔)𝑒) = 𝑥))))
Definition	df-gsum 17070*	Define the group sum (also called "iterated sum") for the structure 𝐺 of a finite sequence of elements whose values are defined by the expression 𝐵 and whose set of indices is 𝐴. It may be viewed as a product (if 𝐺 is a multiplication), a sum (if 𝐺 is an addition) or any other operation. The variable 𝑘 is normally a free variable in 𝐵 (i.e., 𝐵 can be thought of as 𝐵(𝑘)). The definition is meaningful in different contexts, depending on the size of the index set 𝐴 and each demanding different properties of 𝐺. 1. If 𝐴 = ∅ and 𝐺 has an identity element, then the sum equals this identity. See gsum0 18283. 2. If 𝐴 = (𝑀...𝑁) and 𝐺 is any magma, then the sum is the sum of the elements, evaluated left-to-right, i.e., (𝐵(1) + 𝐵(2)) + 𝐵(3), etc. See gsumval2 18285 and gsumnunsn 32420. 3. If 𝐴 is a finite set (or is nonzero for finitely many indices) and 𝐺 is a commutative monoid, then the sum adds up these elements in some order, which is then uniquely defined. See gsumval3 19423. 4. If 𝐴 is an infinite set and 𝐺 is a Hausdorff topological group, then there is a meaningful sum, but Σg cannot handle this case. See df-tsms 23186. Remark: this definition is required here because the symbol Σg is already used in df-prds 17075 and df-imas 17136. The related theorems are provided later, see gsumvalx 18275. (Contributed by FL, 5-Sep-2010.) (Revised by FL, 17-Oct-2011.) (Revised by Mario Carneiro, 7-Dec-2014.)
⊢ Σg = (𝑤 ∈ V, 𝑓 ∈ V ↦ ⦋{𝑥 ∈ (Base‘𝑤) ∣ ∀𝑦 ∈ (Base‘𝑤)((𝑥(+g‘𝑤)𝑦) = 𝑦 ∧ (𝑦(+g‘𝑤)𝑥) = 𝑦)} / 𝑜⦌if(ran 𝑓 ⊆ 𝑜, (0g‘𝑤), if(dom 𝑓 ∈ ran ..., (℩𝑥∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))), (℩𝑥∃𝑔[(◡𝑓 “ (V ∖ 𝑜)) / 𝑦](𝑔:(1...(♯‘𝑦))–1-1-onto→𝑦 ∧ 𝑥 = (seq1((+g‘𝑤), (𝑓 ∘ 𝑔))‘(♯‘𝑦)))))))
Definition	df-topgen 17071*	Define a function that converts a basis to its corresponding topology. Equivalent to the definition of a topology generated by a basis in [Munkres] p. 78 (see tgval2 22014). The first use of this definition is tgval 22013 but the token is used in df-pt 17072. See tgval3 22021 for an alternate expression for the value. (Contributed by NM, 16-Jul-2006.)
⊢ topGen = (𝑥 ∈ V ↦ {𝑦 ∣ 𝑦 ⊆ ∪ (𝑥 ∩ 𝒫 𝑦)})
Definition	df-pt 17072*	Define the product topology on a collection of topologies. For convenience, it is defined on arbitrary collections of sets, expressed as a function from some index set to the subbases of each factor space. (Contributed by Mario Carneiro, 3-Feb-2015.)
⊢ ∏t = (𝑓 ∈ V ↦ (topGen‘{𝑥 ∣ ∃𝑔((𝑔 Fn dom 𝑓 ∧ ∀𝑦 ∈ dom 𝑓(𝑔‘𝑦) ∈ (𝑓‘𝑦) ∧ ∃𝑧 ∈ Fin ∀𝑦 ∈ (dom 𝑓 ∖ 𝑧)(𝑔‘𝑦) = ∪ (𝑓‘𝑦)) ∧ 𝑥 = X𝑦 ∈ dom 𝑓(𝑔‘𝑦))}))
Syntax	cprds 17073	The function constructing structure products.
class Xs
Syntax	cpws 17074	The function constructing structure powers.
class ↑s
Definition	df-prds 17075*	Define a structure product. This can be a product of groups, rings, modules, or ordered topological fields; any unused components will have garbage in them but this is usually not relevant for the purpose of inheriting the structures present in the factors. (Contributed by Stefan O'Rear, 3-Jan-2015.) (Revised by Thierry Arnoux, 15-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ Xs = (𝑠 ∈ V, 𝑟 ∈ V ↦ ⦋X𝑥 ∈ dom 𝑟(Base‘(𝑟‘𝑥)) / 𝑣⦌⦋(𝑓 ∈ 𝑣, 𝑔 ∈ 𝑣 ↦ X𝑥 ∈ dom 𝑟((𝑓‘𝑥)(Hom ‘(𝑟‘𝑥))(𝑔‘𝑥))) / ℎ⦌(({⟨(Base‘ndx), 𝑣⟩, ⟨(+g‘ndx), (𝑓 ∈ 𝑣, 𝑔 ∈ 𝑣 ↦ (𝑥 ∈ dom 𝑟 ↦ ((𝑓‘𝑥)(+g‘(𝑟‘𝑥))(𝑔‘𝑥))))⟩, ⟨(.r‘ndx), (𝑓 ∈ 𝑣, 𝑔 ∈ 𝑣 ↦ (𝑥 ∈ dom 𝑟 ↦ ((𝑓‘𝑥)(.r‘(𝑟‘𝑥))(𝑔‘𝑥))))⟩} ∪ {⟨(Scalar‘ndx), 𝑠⟩, ⟨( ·𝑠 ‘ndx), (𝑓 ∈ (Base‘𝑠), 𝑔 ∈ 𝑣 ↦ (𝑥 ∈ dom 𝑟 ↦ (𝑓( ·𝑠 ‘(𝑟‘𝑥))(𝑔‘𝑥))))⟩, ⟨(·𝑖‘ndx), (𝑓 ∈ 𝑣, 𝑔 ∈ 𝑣 ↦ (𝑠 Σg (𝑥 ∈ dom 𝑟 ↦ ((𝑓‘𝑥)(·𝑖‘(𝑟‘𝑥))(𝑔‘𝑥)))))⟩}) ∪ ({⟨(TopSet‘ndx), (∏t‘(TopOpen ∘ 𝑟))⟩, ⟨(le‘ndx), {⟨𝑓, 𝑔⟩ ∣ ({𝑓, 𝑔} ⊆ 𝑣 ∧ ∀𝑥 ∈ dom 𝑟(𝑓‘𝑥)(le‘(𝑟‘𝑥))(𝑔‘𝑥))}⟩, ⟨(dist‘ndx), (𝑓 ∈ 𝑣, 𝑔 ∈ 𝑣 ↦ sup((ran (𝑥 ∈ dom 𝑟 ↦ ((𝑓‘𝑥)(dist‘(𝑟‘𝑥))(𝑔‘𝑥))) ∪ {0}), ℝ*, < ))⟩} ∪ {⟨(Hom ‘ndx), ℎ⟩, ⟨(comp‘ndx), (𝑎 ∈ (𝑣 × 𝑣), 𝑐 ∈ 𝑣 ↦ (𝑑 ∈ ((2nd ‘𝑎)ℎ𝑐), 𝑒 ∈ (ℎ‘𝑎) ↦ (𝑥 ∈ dom 𝑟 ↦ ((𝑑‘𝑥)(⟨((1st ‘𝑎)‘𝑥), ((2nd ‘𝑎)‘𝑥)⟩(comp‘(𝑟‘𝑥))(𝑐‘𝑥))(𝑒‘𝑥)))))⟩})))
Theorem	reldmprds 17076	The structure product is a well-behaved binary operator. (Contributed by Stefan O'Rear, 7-Jan-2015.) (Revised by Thierry Arnoux, 15-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ Rel dom Xs
Definition	df-pws 17077*	Define a structure power, which is just a structure product where all the factors are the same. (Contributed by Mario Carneiro, 11-Jan-2015.)
⊢ ↑s = (𝑟 ∈ V, 𝑖 ∈ V ↦ ((Scalar‘𝑟)Xs(𝑖 × {𝑟})))
Theorem	prdsbasex 17078*	Lemma for structure products. (Contributed by Mario Carneiro, 3-Jan-2015.)
⊢ 𝐵 = X𝑥 ∈ dom 𝑅(Base‘(𝑅‘𝑥))    ⇒   ⊢ 𝐵 ∈ V
Theorem	imasvalstr 17079	An image structure value is a structure. (Contributed by Stefan O'Rear, 3-Jan-2015.) (Revised by Mario Carneiro, 30-Apr-2015.) (Revised by Thierry Arnoux, 16-Jun-2019.)
⊢ 𝑈 = (({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), × ⟩} ∪ {⟨(Scalar‘ndx), 𝑆⟩, ⟨( ·𝑠 ‘ndx), · ⟩, ⟨(·𝑖‘ndx), , ⟩}) ∪ {⟨(TopSet‘ndx), 𝑂⟩, ⟨(le‘ndx), 𝐿⟩, ⟨(dist‘ndx), 𝐷⟩})    ⇒   ⊢ 𝑈 Struct ⟨1, ;12⟩
Theorem	prdsvalstr 17080	Structure product value is a structure. (Contributed by Stefan O'Rear, 3-Jan-2015.) (Revised by Mario Carneiro, 30-Apr-2015.) (Revised by Thierry Arnoux, 16-Jun-2019.)
⊢ (({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), × ⟩} ∪ {⟨(Scalar‘ndx), 𝑆⟩, ⟨( ·𝑠 ‘ndx), · ⟩, ⟨(·𝑖‘ndx), , ⟩}) ∪ ({⟨(TopSet‘ndx), 𝑂⟩, ⟨(le‘ndx), 𝐿⟩, ⟨(dist‘ndx), 𝐷⟩} ∪ {⟨(Hom ‘ndx), 𝐻⟩, ⟨(comp‘ndx), ∙ ⟩})) Struct ⟨1, ;15⟩
Theorem	prdsbaslem 17081	Lemma for prdsbas 17085 and similar theorems. (Contributed by Mario Carneiro, 7-Jan-2017.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by AV, 12-Jul-2024.)
⊢ (𝜑 → 𝑈 = (({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), × ⟩} ∪ {⟨(Scalar‘ndx), 𝑆⟩, ⟨( ·𝑠 ‘ndx), · ⟩, ⟨(·𝑖‘ndx), , ⟩}) ∪ ({⟨(TopSet‘ndx), 𝑂⟩, ⟨(le‘ndx), 𝐿⟩, ⟨(dist‘ndx), 𝐷⟩} ∪ {⟨(Hom ‘ndx), 𝐻⟩, ⟨(comp‘ndx), ∙ ⟩})))    &   ⊢ 𝐴 = (𝐸‘𝑈)    &   ⊢ 𝐸 = Slot (𝐸‘ndx)    &   ⊢ (𝜑 → 𝑇 ∈ 𝑉)    &   ⊢ {⟨(𝐸‘ndx), 𝑇⟩} ⊆ (({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), × ⟩} ∪ {⟨(Scalar‘ndx), 𝑆⟩, ⟨( ·𝑠 ‘ndx), · ⟩, ⟨(·𝑖‘ndx), , ⟩}) ∪ ({⟨(TopSet‘ndx), 𝑂⟩, ⟨(le‘ndx), 𝐿⟩, ⟨(dist‘ndx), 𝐷⟩} ∪ {⟨(Hom ‘ndx), 𝐻⟩, ⟨(comp‘ndx), ∙ ⟩}))    ⇒   ⊢ (𝜑 → 𝐴 = 𝑇)
Theorem	prdsvallem 17082*	Lemma for prdsval 17083. (Contributed by Stefan O'Rear, 3-Jan-2015.) Extracted from the former proof of prdsval 17083, dependency on df-hom 16912 removed. (Revised by AV, 13-Oct-2024.)
⊢ (𝑓 ∈ 𝑣, 𝑔 ∈ 𝑣 ↦ X𝑥 ∈ dom 𝑟((𝑓‘𝑥)(Hom ‘(𝑟‘𝑥))(𝑔‘𝑥))) ∈ V
Theorem	prdsval 17083*	Value of the structure product. (Contributed by Stefan O'Rear, 3-Jan-2015.) (Revised by Mario Carneiro, 7-Jan-2017.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ 𝐾 = (Base‘𝑆)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ (𝜑 → 𝐵 = X𝑥 ∈ 𝐼 (Base‘(𝑅‘𝑥)))    &   ⊢ (𝜑 → + = (𝑓 ∈ 𝐵, 𝑔 ∈ 𝐵 ↦ (𝑥 ∈ 𝐼 ↦ ((𝑓‘𝑥)(+g‘(𝑅‘𝑥))(𝑔‘𝑥)))))    &   ⊢ (𝜑 → × = (𝑓 ∈ 𝐵, 𝑔 ∈ 𝐵 ↦ (𝑥 ∈ 𝐼 ↦ ((𝑓‘𝑥)(.r‘(𝑅‘𝑥))(𝑔‘𝑥)))))    &   ⊢ (𝜑 → · = (𝑓 ∈ 𝐾, 𝑔 ∈ 𝐵 ↦ (𝑥 ∈ 𝐼 ↦ (𝑓( ·𝑠 ‘(𝑅‘𝑥))(𝑔‘𝑥)))))    &   ⊢ (𝜑 → , = (𝑓 ∈ 𝐵, 𝑔 ∈ 𝐵 ↦ (𝑆 Σg (𝑥 ∈ 𝐼 ↦ ((𝑓‘𝑥)(·𝑖‘(𝑅‘𝑥))(𝑔‘𝑥))))))    &   ⊢ (𝜑 → 𝑂 = (∏t‘(TopOpen ∘ 𝑅)))    &   ⊢ (𝜑 → ≤ = {⟨𝑓, 𝑔⟩ ∣ ({𝑓, 𝑔} ⊆ 𝐵 ∧ ∀𝑥 ∈ 𝐼 (𝑓‘𝑥)(le‘(𝑅‘𝑥))(𝑔‘𝑥))})    &   ⊢ (𝜑 → 𝐷 = (𝑓 ∈ 𝐵, 𝑔 ∈ 𝐵 ↦ sup((ran (𝑥 ∈ 𝐼 ↦ ((𝑓‘𝑥)(dist‘(𝑅‘𝑥))(𝑔‘𝑥))) ∪ {0}), ℝ*, < )))    &   ⊢ (𝜑 → 𝐻 = (𝑓 ∈ 𝐵, 𝑔 ∈ 𝐵 ↦ X𝑥 ∈ 𝐼 ((𝑓‘𝑥)(Hom ‘(𝑅‘𝑥))(𝑔‘𝑥))))    &   ⊢ (𝜑 → ∙ = (𝑎 ∈ (𝐵 × 𝐵), 𝑐 ∈ 𝐵 ↦ (𝑑 ∈ ((2nd ‘𝑎)𝐻𝑐), 𝑒 ∈ (𝐻‘𝑎) ↦ (𝑥 ∈ 𝐼 ↦ ((𝑑‘𝑥)(⟨((1st ‘𝑎)‘𝑥), ((2nd ‘𝑎)‘𝑥)⟩(comp‘(𝑅‘𝑥))(𝑐‘𝑥))(𝑒‘𝑥))))))    &   ⊢ (𝜑 → 𝑆 ∈ 𝑊)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑍)    ⇒   ⊢ (𝜑 → 𝑃 = (({⟨(Base‘ndx), 𝐵⟩, ⟨(+g‘ndx), + ⟩, ⟨(.r‘ndx), × ⟩} ∪ {⟨(Scalar‘ndx), 𝑆⟩, ⟨( ·𝑠 ‘ndx), · ⟩, ⟨(·𝑖‘ndx), , ⟩}) ∪ ({⟨(TopSet‘ndx), 𝑂⟩, ⟨(le‘ndx), ≤ ⟩, ⟨(dist‘ndx), 𝐷⟩} ∪ {⟨(Hom ‘ndx), 𝐻⟩, ⟨(comp‘ndx), ∙ ⟩})))
Theorem	prdssca 17084	Scalar ring of a structure product. (Contributed by Stefan O'Rear, 5-Jan-2015.) (Revised by Mario Carneiro, 15-Aug-2015.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    ⇒   ⊢ (𝜑 → 𝑆 = (Scalar‘𝑃))
Theorem	prdsbas 17085*	Base set of a structure product. (Contributed by Stefan O'Rear, 3-Jan-2015.) (Revised by Mario Carneiro, 15-Aug-2015.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    ⇒   ⊢ (𝜑 → 𝐵 = X𝑥 ∈ 𝐼 (Base‘(𝑅‘𝑥)))
Theorem	prdsplusg 17086*	Addition in a structure product. (Contributed by Stefan O'Rear, 3-Jan-2015.) (Revised by Mario Carneiro, 15-Aug-2015.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ + = (+g‘𝑃)    ⇒   ⊢ (𝜑 → + = (𝑓 ∈ 𝐵, 𝑔 ∈ 𝐵 ↦ (𝑥 ∈ 𝐼 ↦ ((𝑓‘𝑥)(+g‘(𝑅‘𝑥))(𝑔‘𝑥)))))
Theorem	prdsmulr 17087*	Multiplication in a structure product. (Contributed by Mario Carneiro, 11-Jan-2015.) (Revised by Mario Carneiro, 15-Aug-2015.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ · = (.r‘𝑃)    ⇒   ⊢ (𝜑 → · = (𝑓 ∈ 𝐵, 𝑔 ∈ 𝐵 ↦ (𝑥 ∈ 𝐼 ↦ ((𝑓‘𝑥)(.r‘(𝑅‘𝑥))(𝑔‘𝑥)))))
Theorem	prdsvsca 17088*	Scalar multiplication in a structure product. (Contributed by Stefan O'Rear, 5-Jan-2015.) (Revised by Mario Carneiro, 15-Aug-2015.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ 𝐾 = (Base‘𝑆)    &   ⊢ · = ( ·𝑠 ‘𝑃)    ⇒   ⊢ (𝜑 → · = (𝑓 ∈ 𝐾, 𝑔 ∈ 𝐵 ↦ (𝑥 ∈ 𝐼 ↦ (𝑓( ·𝑠 ‘(𝑅‘𝑥))(𝑔‘𝑥)))))
Theorem	prdsip 17089*	Inner product in a structure product. (Contributed by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ , = (·𝑖‘𝑃)    ⇒   ⊢ (𝜑 → , = (𝑓 ∈ 𝐵, 𝑔 ∈ 𝐵 ↦ (𝑆 Σg (𝑥 ∈ 𝐼 ↦ ((𝑓‘𝑥)(·𝑖‘(𝑅‘𝑥))(𝑔‘𝑥))))))
Theorem	prdsle 17090*	Structure product weak ordering. (Contributed by Mario Carneiro, 15-Aug-2015.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ ≤ = (le‘𝑃)    ⇒   ⊢ (𝜑 → ≤ = {⟨𝑓, 𝑔⟩ ∣ ({𝑓, 𝑔} ⊆ 𝐵 ∧ ∀𝑥 ∈ 𝐼 (𝑓‘𝑥)(le‘(𝑅‘𝑥))(𝑔‘𝑥))})
Theorem	prdsless 17091	Closure of the order relation on a structure product. (Contributed by Mario Carneiro, 16-Aug-2015.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ ≤ = (le‘𝑃)    ⇒   ⊢ (𝜑 → ≤ ⊆ (𝐵 × 𝐵))
Theorem	prdsds 17092*	Structure product distance function. (Contributed by Mario Carneiro, 15-Aug-2015.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ 𝐷 = (dist‘𝑃)    ⇒   ⊢ (𝜑 → 𝐷 = (𝑓 ∈ 𝐵, 𝑔 ∈ 𝐵 ↦ sup((ran (𝑥 ∈ 𝐼 ↦ ((𝑓‘𝑥)(dist‘(𝑅‘𝑥))(𝑔‘𝑥))) ∪ {0}), ℝ*, < )))
Theorem	prdsdsfn 17093	Structure product distance function. (Contributed by Mario Carneiro, 15-Sep-2015.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ 𝐷 = (dist‘𝑃)    ⇒   ⊢ (𝜑 → 𝐷 Fn (𝐵 × 𝐵))
Theorem	prdstset 17094	Structure product topology. (Contributed by Mario Carneiro, 15-Aug-2015.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ 𝑂 = (TopSet‘𝑃)    ⇒   ⊢ (𝜑 → 𝑂 = (∏t‘(TopOpen ∘ 𝑅)))
Theorem	prdshom 17095*	Structure product hom-sets. (Contributed by Mario Carneiro, 7-Jan-2017.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ 𝐻 = (Hom ‘𝑃)    ⇒   ⊢ (𝜑 → 𝐻 = (𝑓 ∈ 𝐵, 𝑔 ∈ 𝐵 ↦ X𝑥 ∈ 𝐼 ((𝑓‘𝑥)(Hom ‘(𝑅‘𝑥))(𝑔‘𝑥))))
Theorem	prdsco 17096*	Structure product composition operation. (Contributed by Mario Carneiro, 7-Jan-2017.) (Revised by Thierry Arnoux, 16-Jun-2019.) (Revised by Zhi Wang, 18-Aug-2024.)
⊢ 𝑃 = (𝑆Xs𝑅)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑅 ∈ 𝑊)    &   ⊢ 𝐵 = (Base‘𝑃)    &   ⊢ (𝜑 → dom 𝑅 = 𝐼)    &   ⊢ 𝐻 = (Hom ‘𝑃)    &   ⊢ ∙ = (comp‘𝑃)    ⇒   ⊢ (𝜑 → ∙ = (𝑎 ∈ (𝐵 × 𝐵), 𝑐 ∈ 𝐵 ↦ (𝑑 ∈ ((2nd ‘𝑎)𝐻𝑐), 𝑒 ∈ (𝐻‘𝑎) ↦ (𝑥 ∈ 𝐼 ↦ ((𝑑‘𝑥)(⟨((1st ‘𝑎)‘𝑥), ((2nd ‘𝑎)‘𝑥)⟩(comp‘(𝑅‘𝑥))(𝑐‘𝑥))(𝑒‘𝑥))))))
Theorem	prdsbas2 17097*	The base set of a structure product is an indexed set product. (Contributed by Stefan O'Rear, 10-Jan-2015.) (Revised by Mario Carneiro, 15-Aug-2015.)
⊢ 𝑌 = (𝑆Xs𝑅)    &   ⊢ 𝐵 = (Base‘𝑌)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝑊)    &   ⊢ (𝜑 → 𝑅 Fn 𝐼)    ⇒   ⊢ (𝜑 → 𝐵 = X𝑥 ∈ 𝐼 (Base‘(𝑅‘𝑥)))
Theorem	prdsbasmpt 17098*	A constructed tuple is a point in a structure product iff each coordinate is in the proper base set. (Contributed by Stefan O'Rear, 10-Jan-2015.)
⊢ 𝑌 = (𝑆Xs𝑅)    &   ⊢ 𝐵 = (Base‘𝑌)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝑊)    &   ⊢ (𝜑 → 𝑅 Fn 𝐼)    ⇒   ⊢ (𝜑 → ((𝑥 ∈ 𝐼 ↦ 𝑈) ∈ 𝐵 ↔ ∀𝑥 ∈ 𝐼 𝑈 ∈ (Base‘(𝑅‘𝑥))))
Theorem	prdsbasfn 17099	Points in the structure product are functions; use this with dffn5 6810 to establish equalities. (Contributed by Stefan O'Rear, 10-Jan-2015.)
⊢ 𝑌 = (𝑆Xs𝑅)    &   ⊢ 𝐵 = (Base‘𝑌)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝑊)    &   ⊢ (𝜑 → 𝑅 Fn 𝐼)    &   ⊢ (𝜑 → 𝑇 ∈ 𝐵)    ⇒   ⊢ (𝜑 → 𝑇 Fn 𝐼)
Theorem	prdsbasprj 17100	Each point in a structure product restricts on each coordinate to the relevant base set. (Contributed by Stefan O'Rear, 10-Jan-2015.)
⊢ 𝑌 = (𝑆Xs𝑅)    &   ⊢ 𝐵 = (Base‘𝑌)    &   ⊢ (𝜑 → 𝑆 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐼 ∈ 𝑊)    &   ⊢ (𝜑 → 𝑅 Fn 𝐼)    &   ⊢ (𝜑 → 𝑇 ∈ 𝐵)    &   ⊢ (𝜑 → 𝐽 ∈ 𝐼)    ⇒   ⊢ (𝜑 → (𝑇‘𝐽) ∈ (Base‘(𝑅‘𝐽)))