Theorem isobs 20908

Description: The predicate "is an orthonormal basis" (over a pre-Hilbert space). (Contributed by Mario Carneiro, 23-Oct-2015.)

Hypotheses

Ref	Expression
isobs.v	⊢ 𝑉 = (Base‘𝑊)
isobs.h	⊢ , = (·𝑖‘𝑊)
isobs.f	⊢ 𝐹 = (Scalar‘𝑊)
isobs.u	⊢ 1 = (1r‘𝐹)
isobs.z	⊢ 0 = (0g‘𝐹)
isobs.o	⊢ ⊥ = (ocv‘𝑊)
isobs.y	⊢ 𝑌 = (0g‘𝑊)

Assertion

Ref	Expression
isobs	⊢ (𝐵 ∈ (OBasis‘𝑊) ↔ (𝑊 ∈ PreHil ∧ 𝐵 ⊆ 𝑉 ∧ (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝐵) = {𝑌})))

Distinct variable groups:   𝑥,𝑦, ,   𝑥, 0 ,𝑦   𝑥, 1 ,𝑦   𝑥,𝐵,𝑦   𝑥,𝑊,𝑦

Allowed substitution hints:   𝐹(𝑥,𝑦)   ⊥ (𝑥,𝑦)   𝑉(𝑥,𝑦)   𝑌(𝑥,𝑦)

Proof of Theorem isobs

Dummy variables ℎ 𝑏 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-obs 20893	. . . 4 ⊢ OBasis = (ℎ ∈ PreHil ↦ {𝑏 ∈ 𝒫 (Base‘ℎ) ∣ (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥(·𝑖‘ℎ)𝑦) = if(𝑥 = 𝑦, (1r‘(Scalar‘ℎ)), (0g‘(Scalar‘ℎ))) ∧ ((ocv‘ℎ)‘𝑏) = {(0g‘ℎ)})})
2	1	mptrcl 6878	. . 3 ⊢ (𝐵 ∈ (OBasis‘𝑊) → 𝑊 ∈ PreHil)
3		fveq2 6768	. . . . . . . . 9 ⊢ (ℎ = 𝑊 → (Base‘ℎ) = (Base‘𝑊))
4		isobs.v	. . . . . . . . 9 ⊢ 𝑉 = (Base‘𝑊)
5	3, 4	eqtr4di 2797	. . . . . . . 8 ⊢ (ℎ = 𝑊 → (Base‘ℎ) = 𝑉)
6	5	pweqd 4557	. . . . . . 7 ⊢ (ℎ = 𝑊 → 𝒫 (Base‘ℎ) = 𝒫 𝑉)
7		fveq2 6768	. . . . . . . . . . . 12 ⊢ (ℎ = 𝑊 → (·𝑖‘ℎ) = (·𝑖‘𝑊))
8		isobs.h	. . . . . . . . . . . 12 ⊢ , = (·𝑖‘𝑊)
9	7, 8	eqtr4di 2797	. . . . . . . . . . 11 ⊢ (ℎ = 𝑊 → (·𝑖‘ℎ) = , )
10	9	oveqd 7285	. . . . . . . . . 10 ⊢ (ℎ = 𝑊 → (𝑥(·𝑖‘ℎ)𝑦) = (𝑥 , 𝑦))
11		fveq2 6768	. . . . . . . . . . . . . 14 ⊢ (ℎ = 𝑊 → (Scalar‘ℎ) = (Scalar‘𝑊))
12		isobs.f	. . . . . . . . . . . . . 14 ⊢ 𝐹 = (Scalar‘𝑊)
13	11, 12	eqtr4di 2797	. . . . . . . . . . . . 13 ⊢ (ℎ = 𝑊 → (Scalar‘ℎ) = 𝐹)
14	13	fveq2d 6772	. . . . . . . . . . . 12 ⊢ (ℎ = 𝑊 → (1r‘(Scalar‘ℎ)) = (1r‘𝐹))
15		isobs.u	. . . . . . . . . . . 12 ⊢ 1 = (1r‘𝐹)
16	14, 15	eqtr4di 2797	. . . . . . . . . . 11 ⊢ (ℎ = 𝑊 → (1r‘(Scalar‘ℎ)) = 1 )
17	13	fveq2d 6772	. . . . . . . . . . . 12 ⊢ (ℎ = 𝑊 → (0g‘(Scalar‘ℎ)) = (0g‘𝐹))
18		isobs.z	. . . . . . . . . . . 12 ⊢ 0 = (0g‘𝐹)
19	17, 18	eqtr4di 2797	. . . . . . . . . . 11 ⊢ (ℎ = 𝑊 → (0g‘(Scalar‘ℎ)) = 0 )
20	16, 19	ifeq12d 4485	. . . . . . . . . 10 ⊢ (ℎ = 𝑊 → if(𝑥 = 𝑦, (1r‘(Scalar‘ℎ)), (0g‘(Scalar‘ℎ))) = if(𝑥 = 𝑦, 1 , 0 ))
21	10, 20	eqeq12d 2755	. . . . . . . . 9 ⊢ (ℎ = 𝑊 → ((𝑥(·𝑖‘ℎ)𝑦) = if(𝑥 = 𝑦, (1r‘(Scalar‘ℎ)), (0g‘(Scalar‘ℎ))) ↔ (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 )))
22	21	2ralbidv 3124	. . . . . . . 8 ⊢ (ℎ = 𝑊 → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥(·𝑖‘ℎ)𝑦) = if(𝑥 = 𝑦, (1r‘(Scalar‘ℎ)), (0g‘(Scalar‘ℎ))) ↔ ∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 )))
23		fveq2 6768	. . . . . . . . . . 11 ⊢ (ℎ = 𝑊 → (ocv‘ℎ) = (ocv‘𝑊))
24		isobs.o	. . . . . . . . . . 11 ⊢ ⊥ = (ocv‘𝑊)
25	23, 24	eqtr4di 2797	. . . . . . . . . 10 ⊢ (ℎ = 𝑊 → (ocv‘ℎ) = ⊥ )
26	25	fveq1d 6770	. . . . . . . . 9 ⊢ (ℎ = 𝑊 → ((ocv‘ℎ)‘𝑏) = ( ⊥ ‘𝑏))
27		fveq2 6768	. . . . . . . . . . 11 ⊢ (ℎ = 𝑊 → (0g‘ℎ) = (0g‘𝑊))
28		isobs.y	. . . . . . . . . . 11 ⊢ 𝑌 = (0g‘𝑊)
29	27, 28	eqtr4di 2797	. . . . . . . . . 10 ⊢ (ℎ = 𝑊 → (0g‘ℎ) = 𝑌)
30	29	sneqd 4578	. . . . . . . . 9 ⊢ (ℎ = 𝑊 → {(0g‘ℎ)} = {𝑌})
31	26, 30	eqeq12d 2755	. . . . . . . 8 ⊢ (ℎ = 𝑊 → (((ocv‘ℎ)‘𝑏) = {(0g‘ℎ)} ↔ ( ⊥ ‘𝑏) = {𝑌}))
32	22, 31	anbi12d 630	. . . . . . 7 ⊢ (ℎ = 𝑊 → ((∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥(·𝑖‘ℎ)𝑦) = if(𝑥 = 𝑦, (1r‘(Scalar‘ℎ)), (0g‘(Scalar‘ℎ))) ∧ ((ocv‘ℎ)‘𝑏) = {(0g‘ℎ)}) ↔ (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝑏) = {𝑌})))
33	6, 32	rabeqbidv 3418	. . . . . 6 ⊢ (ℎ = 𝑊 → {𝑏 ∈ 𝒫 (Base‘ℎ) ∣ (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥(·𝑖‘ℎ)𝑦) = if(𝑥 = 𝑦, (1r‘(Scalar‘ℎ)), (0g‘(Scalar‘ℎ))) ∧ ((ocv‘ℎ)‘𝑏) = {(0g‘ℎ)})} = {𝑏 ∈ 𝒫 𝑉 ∣ (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝑏) = {𝑌})})
34	4	fvexi 6782	. . . . . . . 8 ⊢ 𝑉 ∈ V
35	34	pwex 5306	. . . . . . 7 ⊢ 𝒫 𝑉 ∈ V
36	35	rabex 5259	. . . . . 6 ⊢ {𝑏 ∈ 𝒫 𝑉 ∣ (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝑏) = {𝑌})} ∈ V
37	33, 1, 36	fvmpt 6869	. . . . 5 ⊢ (𝑊 ∈ PreHil → (OBasis‘𝑊) = {𝑏 ∈ 𝒫 𝑉 ∣ (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝑏) = {𝑌})})
38	37	eleq2d 2825	. . . 4 ⊢ (𝑊 ∈ PreHil → (𝐵 ∈ (OBasis‘𝑊) ↔ 𝐵 ∈ {𝑏 ∈ 𝒫 𝑉 ∣ (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝑏) = {𝑌})}))
39		raleq 3340	. . . . . . . 8 ⊢ (𝑏 = 𝐵 → (∀𝑦 ∈ 𝑏 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ↔ ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 )))
40	39	raleqbi1dv 3338	. . . . . . 7 ⊢ (𝑏 = 𝐵 → (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 )))
41		fveqeq2 6777	. . . . . . 7 ⊢ (𝑏 = 𝐵 → (( ⊥ ‘𝑏) = {𝑌} ↔ ( ⊥ ‘𝐵) = {𝑌}))
42	40, 41	anbi12d 630	. . . . . 6 ⊢ (𝑏 = 𝐵 → ((∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝑏) = {𝑌}) ↔ (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝐵) = {𝑌})))
43	42	elrab 3625	. . . . 5 ⊢ (𝐵 ∈ {𝑏 ∈ 𝒫 𝑉 ∣ (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝑏) = {𝑌})} ↔ (𝐵 ∈ 𝒫 𝑉 ∧ (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝐵) = {𝑌})))
44	34	elpw2 5272	. . . . . 6 ⊢ (𝐵 ∈ 𝒫 𝑉 ↔ 𝐵 ⊆ 𝑉)
45	44	anbi1i 623	. . . . 5 ⊢ ((𝐵 ∈ 𝒫 𝑉 ∧ (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝐵) = {𝑌})) ↔ (𝐵 ⊆ 𝑉 ∧ (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝐵) = {𝑌})))
46	43, 45	bitri 274	. . . 4 ⊢ (𝐵 ∈ {𝑏 ∈ 𝒫 𝑉 ∣ (∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝑏) = {𝑌})} ↔ (𝐵 ⊆ 𝑉 ∧ (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝐵) = {𝑌})))
47	38, 46	bitrdi 286	. . 3 ⊢ (𝑊 ∈ PreHil → (𝐵 ∈ (OBasis‘𝑊) ↔ (𝐵 ⊆ 𝑉 ∧ (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝐵) = {𝑌}))))
48	2, 47	biadanii 818	. 2 ⊢ (𝐵 ∈ (OBasis‘𝑊) ↔ (𝑊 ∈ PreHil ∧ (𝐵 ⊆ 𝑉 ∧ (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝐵) = {𝑌}))))
49		3anass 1093	. 2 ⊢ ((𝑊 ∈ PreHil ∧ 𝐵 ⊆ 𝑉 ∧ (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝐵) = {𝑌})) ↔ (𝑊 ∈ PreHil ∧ (𝐵 ⊆ 𝑉 ∧ (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝐵) = {𝑌}))))
50	48, 49	bitr4i 277	1 ⊢ (𝐵 ∈ (OBasis‘𝑊) ↔ (𝑊 ∈ PreHil ∧ 𝐵 ⊆ 𝑉 ∧ (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 , 𝑦) = if(𝑥 = 𝑦, 1 , 0 ) ∧ ( ⊥ ‘𝐵) = {𝑌})))

Syntax hints:   ↔ wb 205   ∧ wa 395   ∧ w3a 1085   = wceq 1541   ∈ wcel 2109  ∀wral 3065  {crab 3069   ⊆ wss 3891  ifcif 4464  𝒫 cpw 4538  {csn 4566  ‘cfv 6430  (class class class)co 7268  Basecbs 16893  Scalarcsca 16946  ·_𝑖cip 16948  0_gc0g 17131  1_rcur 19718  PreHilcphl 20810  ocvcocv 20846  OBasiscobs 20890

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1801  ax-4 1815  ax-5 1916  ax-6 1974  ax-7 2014  ax-8 2111  ax-9 2119  ax-10 2140  ax-11 2157  ax-12 2174  ax-ext 2710  ax-sep 5226  ax-nul 5233  ax-pow 5291  ax-pr 5355

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 844  df-3an 1087  df-tru 1544  df-fal 1554  df-ex 1786  df-nf 1790  df-sb 2071  df-mo 2541  df-eu 2570  df-clab 2717  df-cleq 2731  df-clel 2817  df-nfc 2890  df-ne 2945  df-ral 3070  df-rex 3071  df-rab 3074  df-v 3432  df-dif 3894  df-un 3896  df-in 3898  df-ss 3908  df-nul 4262  df-if 4465  df-pw 4540  df-sn 4567  df-pr 4569  df-op 4573  df-uni 4845  df-br 5079  df-opab 5141  df-mpt 5162  df-id 5488  df-xp 5594  df-rel 5595  df-cnv 5596  df-co 5597  df-dm 5598  df-rn 5599  df-res 5600  df-ima 5601  df-iota 6388  df-fun 6432  df-fv 6438  df-ov 7271  df-obs 20893

This theorem is referenced by:  obsip  20909  obsrcl  20911  obsss  20912  obsocv  20914