Theorem fngsum 13090

Description: Iterated sum has a universal domain. (Contributed by Jim Kingdon, 28-Jun-2025.)

Assertion

Ref	Expression
fngsum	⊢ Σg Fn (V × V)

Proof of Theorem fngsum

Dummy variables 𝑓 𝑚 𝑛 𝑤 𝑥 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-igsum 12961	. 2 ⊢ Σg = (𝑤 ∈ V, 𝑓 ∈ V ↦ (℩𝑥((dom 𝑓 = ∅ ∧ 𝑥 = (0g‘𝑤)) ∨ ∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)))))
2		unab 3431	. . . 4 ⊢ ({𝑥 ∣ (dom 𝑓 = ∅ ∧ 𝑥 = (0g‘𝑤))} ∪ {𝑥 ∣ ∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))}) = {𝑥 ∣ ((dom 𝑓 = ∅ ∧ 𝑥 = (0g‘𝑤)) ∨ ∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)))}
3		df-sn 3629	. . . . . . 7 ⊢ {(0g‘𝑤)} = {𝑥 ∣ 𝑥 = (0g‘𝑤)}
4		fn0g 13077	. . . . . . . . 9 ⊢ 0g Fn V
5		vex 2766	. . . . . . . . 9 ⊢ 𝑤 ∈ V
6		funfvex 5578	. . . . . . . . . 10 ⊢ ((Fun 0g ∧ 𝑤 ∈ dom 0g) → (0g‘𝑤) ∈ V)
7	6	funfni 5361	. . . . . . . . 9 ⊢ ((0g Fn V ∧ 𝑤 ∈ V) → (0g‘𝑤) ∈ V)
8	4, 5, 7	mp2an 426	. . . . . . . 8 ⊢ (0g‘𝑤) ∈ V
9	8	snex 4219	. . . . . . 7 ⊢ {(0g‘𝑤)} ∈ V
10	3, 9	eqeltrri 2270	. . . . . 6 ⊢ {𝑥 ∣ 𝑥 = (0g‘𝑤)} ∈ V
11		simpr 110	. . . . . . 7 ⊢ ((dom 𝑓 = ∅ ∧ 𝑥 = (0g‘𝑤)) → 𝑥 = (0g‘𝑤))
12	11	ss2abi 3256	. . . . . 6 ⊢ {𝑥 ∣ (dom 𝑓 = ∅ ∧ 𝑥 = (0g‘𝑤))} ⊆ {𝑥 ∣ 𝑥 = (0g‘𝑤)}
13	10, 12	ssexi 4172	. . . . 5 ⊢ {𝑥 ∣ (dom 𝑓 = ∅ ∧ 𝑥 = (0g‘𝑤))} ∈ V
14		zex 9352	. . . . . . 7 ⊢ ℤ ∈ V
15	14, 14	ab2rexex 6197	. . . . . 6 ⊢ {𝑥 ∣ ∃𝑚 ∈ ℤ ∃𝑛 ∈ ℤ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)} ∈ V
16		df-rex 2481	. . . . . . . . . . . 12 ⊢ (∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)) ↔ ∃𝑛(𝑛 ∈ (ℤ≥‘𝑚) ∧ (dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))))
17		eluzel2 9623	. . . . . . . . . . . . . . . 16 ⊢ (𝑛 ∈ (ℤ≥‘𝑚) → 𝑚 ∈ ℤ)
18		eluzelz 9627	. . . . . . . . . . . . . . . 16 ⊢ (𝑛 ∈ (ℤ≥‘𝑚) → 𝑛 ∈ ℤ)
19	17, 18	jca 306	. . . . . . . . . . . . . . 15 ⊢ (𝑛 ∈ (ℤ≥‘𝑚) → (𝑚 ∈ ℤ ∧ 𝑛 ∈ ℤ))
20		simpr 110	. . . . . . . . . . . . . . 15 ⊢ ((dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)) → 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))
21	19, 20	anim12i 338	. . . . . . . . . . . . . 14 ⊢ ((𝑛 ∈ (ℤ≥‘𝑚) ∧ (dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))) → ((𝑚 ∈ ℤ ∧ 𝑛 ∈ ℤ) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)))
22		anass 401	. . . . . . . . . . . . . 14 ⊢ (((𝑚 ∈ ℤ ∧ 𝑛 ∈ ℤ) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)) ↔ (𝑚 ∈ ℤ ∧ (𝑛 ∈ ℤ ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))))
23	21, 22	sylib 122	. . . . . . . . . . . . 13 ⊢ ((𝑛 ∈ (ℤ≥‘𝑚) ∧ (dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))) → (𝑚 ∈ ℤ ∧ (𝑛 ∈ ℤ ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))))
24	23	eximi 1614	. . . . . . . . . . . 12 ⊢ (∃𝑛(𝑛 ∈ (ℤ≥‘𝑚) ∧ (dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))) → ∃𝑛(𝑚 ∈ ℤ ∧ (𝑛 ∈ ℤ ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))))
25	16, 24	sylbi 121	. . . . . . . . . . 11 ⊢ (∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)) → ∃𝑛(𝑚 ∈ ℤ ∧ (𝑛 ∈ ℤ ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))))
26		19.42v 1921	. . . . . . . . . . 11 ⊢ (∃𝑛(𝑚 ∈ ℤ ∧ (𝑛 ∈ ℤ ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))) ↔ (𝑚 ∈ ℤ ∧ ∃𝑛(𝑛 ∈ ℤ ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))))
27	25, 26	sylib 122	. . . . . . . . . 10 ⊢ (∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)) → (𝑚 ∈ ℤ ∧ ∃𝑛(𝑛 ∈ ℤ ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))))
28		df-rex 2481	. . . . . . . . . . 11 ⊢ (∃𝑛 ∈ ℤ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛) ↔ ∃𝑛(𝑛 ∈ ℤ ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)))
29	28	anbi2i 457	. . . . . . . . . 10 ⊢ ((𝑚 ∈ ℤ ∧ ∃𝑛 ∈ ℤ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)) ↔ (𝑚 ∈ ℤ ∧ ∃𝑛(𝑛 ∈ ℤ ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))))
30	27, 29	sylibr 134	. . . . . . . . 9 ⊢ (∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)) → (𝑚 ∈ ℤ ∧ ∃𝑛 ∈ ℤ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)))
31	30	eximi 1614	. . . . . . . 8 ⊢ (∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)) → ∃𝑚(𝑚 ∈ ℤ ∧ ∃𝑛 ∈ ℤ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)))
32		df-rex 2481	. . . . . . . 8 ⊢ (∃𝑚 ∈ ℤ ∃𝑛 ∈ ℤ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛) ↔ ∃𝑚(𝑚 ∈ ℤ ∧ ∃𝑛 ∈ ℤ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)))
33	31, 32	sylibr 134	. . . . . . 7 ⊢ (∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)) → ∃𝑚 ∈ ℤ ∃𝑛 ∈ ℤ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))
34	33	ss2abi 3256	. . . . . 6 ⊢ {𝑥 ∣ ∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))} ⊆ {𝑥 ∣ ∃𝑚 ∈ ℤ ∃𝑛 ∈ ℤ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)}
35	15, 34	ssexi 4172	. . . . 5 ⊢ {𝑥 ∣ ∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))} ∈ V
36	13, 35	unex 4477	. . . 4 ⊢ ({𝑥 ∣ (dom 𝑓 = ∅ ∧ 𝑥 = (0g‘𝑤))} ∪ {𝑥 ∣ ∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛))}) ∈ V
37	2, 36	eqeltrri 2270	. . 3 ⊢ {𝑥 ∣ ((dom 𝑓 = ∅ ∧ 𝑥 = (0g‘𝑤)) ∨ ∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)))} ∈ V
38		iotaexab 5238	. . 3 ⊢ ({𝑥 ∣ ((dom 𝑓 = ∅ ∧ 𝑥 = (0g‘𝑤)) ∨ ∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)))} ∈ V → (℩𝑥((dom 𝑓 = ∅ ∧ 𝑥 = (0g‘𝑤)) ∨ ∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)))) ∈ V)
39	37, 38	ax-mp 5	. 2 ⊢ (℩𝑥((dom 𝑓 = ∅ ∧ 𝑥 = (0g‘𝑤)) ∨ ∃𝑚∃𝑛 ∈ (ℤ≥‘𝑚)(dom 𝑓 = (𝑚...𝑛) ∧ 𝑥 = (seq𝑚((+g‘𝑤), 𝑓)‘𝑛)))) ∈ V
40	1, 39	fnmpoi 6270	1 ⊢ Σg Fn (V × V)

Syntax hints:   ∧ wa 104   ∨ wo 709   = wceq 1364  ∃wex 1506   ∈ wcel 2167  {cab 2182  ∃wrex 2476  Vcvv 2763   ∪ cun 3155  ∅c0 3451  {csn 3623   × cxp 4662  dom cdm 4664  ℩cio 5218   Fn wfn 5254  ‘cfv 5259  (class class class)co 5925  ℤcz 9343  ℤ_≥cuz 9618  ...cfz 10100  seqcseq 10556  +_gcplusg 12780  0_gc0g 12958   Σ_g cgsu 12959

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 710  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-13 2169  ax-14 2170  ax-ext 2178  ax-coll 4149  ax-sep 4152  ax-pow 4208  ax-pr 4243  ax-un 4469  ax-cnex 7987  ax-resscn 7988  ax-1re 7990  ax-addrcl 7993

This theorem depends on definitions:  df-bi 117  df-3or 981  df-3an 982  df-tru 1367  df-nf 1475  df-sb 1777  df-eu 2048  df-mo 2049  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-ral 2480  df-rex 2481  df-reu 2482  df-rab 2484  df-v 2765  df-sbc 2990  df-csb 3085  df-un 3161  df-in 3163  df-ss 3170  df-pw 3608  df-sn 3629  df-pr 3630  df-op 3632  df-uni 3841  df-int 3876  df-iun 3919  df-br 4035  df-opab 4096  df-mpt 4097  df-id 4329  df-xp 4670  df-rel 4671  df-cnv 4672  df-co 4673  df-dm 4674  df-rn 4675  df-res 4676  df-ima 4677  df-iota 5220  df-fun 5261  df-fn 5262  df-f 5263  df-f1 5264  df-fo 5265  df-f1o 5266  df-fv 5267  df-riota 5880  df-ov 5928  df-oprab 5929  df-mpo 5930  df-1st 6207  df-2nd 6208  df-neg 8217  df-inn 9008  df-z 9344  df-uz 9619  df-ndx 12706  df-slot 12707  df-base 12709  df-0g 12960  df-igsum 12961

This theorem is referenced by: (None)