Theorem naddov2 8643

Description: Alternate expression for natural addition. (Contributed by Scott Fenton, 26-Aug-2024.)

Assertion

Ref	Expression
naddov2	⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +no 𝐵) = ∩ {𝑥 ∈ On ∣ (∀𝑦 ∈ 𝐵 (𝐴 +no 𝑦) ∈ 𝑥 ∧ ∀𝑧 ∈ 𝐴 (𝑧 +no 𝐵) ∈ 𝑥)})

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝑦,𝐴   𝑧,𝐴   𝑦,𝐵   𝑧,𝐵   𝑥,𝑦   𝑥,𝑧

Proof of Theorem naddov2

Dummy variable 𝑡 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		naddov 8642	. 2 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +no 𝐵) = ∩ {𝑥 ∈ On ∣ (( +no “ ({𝐴} × 𝐵)) ⊆ 𝑥 ∧ ( +no “ (𝐴 × {𝐵})) ⊆ 𝑥)})
2		snssi 4772	. . . . . . . . 9 ⊢ (𝐴 ∈ On → {𝐴} ⊆ On)
3		onss 7761	. . . . . . . . 9 ⊢ (𝐵 ∈ On → 𝐵 ⊆ On)
4		xpss12 5653	. . . . . . . . 9 ⊢ (({𝐴} ⊆ On ∧ 𝐵 ⊆ On) → ({𝐴} × 𝐵) ⊆ (On × On))
5	2, 3, 4	syl2an 596	. . . . . . . 8 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ({𝐴} × 𝐵) ⊆ (On × On))
6		naddfn 8639	. . . . . . . . 9 ⊢ +no Fn (On × On)
7	6	fndmi 6622	. . . . . . . 8 ⊢ dom +no = (On × On)
8	5, 7	sseqtrrdi 3988	. . . . . . 7 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ({𝐴} × 𝐵) ⊆ dom +no )
9		fnfun 6618	. . . . . . . . 9 ⊢ ( +no Fn (On × On) → Fun +no )
10	6, 9	ax-mp 5	. . . . . . . 8 ⊢ Fun +no
11		funimassov 7566	. . . . . . . 8 ⊢ ((Fun +no ∧ ({𝐴} × 𝐵) ⊆ dom +no ) → (( +no “ ({𝐴} × 𝐵)) ⊆ 𝑥 ↔ ∀𝑡 ∈ {𝐴}∀𝑦 ∈ 𝐵 (𝑡 +no 𝑦) ∈ 𝑥))
12	10, 11	mpan 690	. . . . . . 7 ⊢ (({𝐴} × 𝐵) ⊆ dom +no → (( +no “ ({𝐴} × 𝐵)) ⊆ 𝑥 ↔ ∀𝑡 ∈ {𝐴}∀𝑦 ∈ 𝐵 (𝑡 +no 𝑦) ∈ 𝑥))
13	8, 12	syl 17	. . . . . 6 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (( +no “ ({𝐴} × 𝐵)) ⊆ 𝑥 ↔ ∀𝑡 ∈ {𝐴}∀𝑦 ∈ 𝐵 (𝑡 +no 𝑦) ∈ 𝑥))
14		oveq1 7394	. . . . . . . . . 10 ⊢ (𝑡 = 𝐴 → (𝑡 +no 𝑦) = (𝐴 +no 𝑦))
15	14	eleq1d 2813	. . . . . . . . 9 ⊢ (𝑡 = 𝐴 → ((𝑡 +no 𝑦) ∈ 𝑥 ↔ (𝐴 +no 𝑦) ∈ 𝑥))
16	15	ralbidv 3156	. . . . . . . 8 ⊢ (𝑡 = 𝐴 → (∀𝑦 ∈ 𝐵 (𝑡 +no 𝑦) ∈ 𝑥 ↔ ∀𝑦 ∈ 𝐵 (𝐴 +no 𝑦) ∈ 𝑥))
17	16	ralsng 4639	. . . . . . 7 ⊢ (𝐴 ∈ On → (∀𝑡 ∈ {𝐴}∀𝑦 ∈ 𝐵 (𝑡 +no 𝑦) ∈ 𝑥 ↔ ∀𝑦 ∈ 𝐵 (𝐴 +no 𝑦) ∈ 𝑥))
18	17	adantr 480	. . . . . 6 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (∀𝑡 ∈ {𝐴}∀𝑦 ∈ 𝐵 (𝑡 +no 𝑦) ∈ 𝑥 ↔ ∀𝑦 ∈ 𝐵 (𝐴 +no 𝑦) ∈ 𝑥))
19	13, 18	bitrd 279	. . . . 5 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (( +no “ ({𝐴} × 𝐵)) ⊆ 𝑥 ↔ ∀𝑦 ∈ 𝐵 (𝐴 +no 𝑦) ∈ 𝑥))
20		onss 7761	. . . . . . . . 9 ⊢ (𝐴 ∈ On → 𝐴 ⊆ On)
21		snssi 4772	. . . . . . . . 9 ⊢ (𝐵 ∈ On → {𝐵} ⊆ On)
22		xpss12 5653	. . . . . . . . 9 ⊢ ((𝐴 ⊆ On ∧ {𝐵} ⊆ On) → (𝐴 × {𝐵}) ⊆ (On × On))
23	20, 21, 22	syl2an 596	. . . . . . . 8 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 × {𝐵}) ⊆ (On × On))
24	23, 7	sseqtrrdi 3988	. . . . . . 7 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 × {𝐵}) ⊆ dom +no )
25		funimassov 7566	. . . . . . . 8 ⊢ ((Fun +no ∧ (𝐴 × {𝐵}) ⊆ dom +no ) → (( +no “ (𝐴 × {𝐵})) ⊆ 𝑥 ↔ ∀𝑧 ∈ 𝐴 ∀𝑡 ∈ {𝐵} (𝑧 +no 𝑡) ∈ 𝑥))
26	10, 25	mpan 690	. . . . . . 7 ⊢ ((𝐴 × {𝐵}) ⊆ dom +no → (( +no “ (𝐴 × {𝐵})) ⊆ 𝑥 ↔ ∀𝑧 ∈ 𝐴 ∀𝑡 ∈ {𝐵} (𝑧 +no 𝑡) ∈ 𝑥))
27	24, 26	syl 17	. . . . . 6 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (( +no “ (𝐴 × {𝐵})) ⊆ 𝑥 ↔ ∀𝑧 ∈ 𝐴 ∀𝑡 ∈ {𝐵} (𝑧 +no 𝑡) ∈ 𝑥))
28		oveq2 7395	. . . . . . . . . 10 ⊢ (𝑡 = 𝐵 → (𝑧 +no 𝑡) = (𝑧 +no 𝐵))
29	28	eleq1d 2813	. . . . . . . . 9 ⊢ (𝑡 = 𝐵 → ((𝑧 +no 𝑡) ∈ 𝑥 ↔ (𝑧 +no 𝐵) ∈ 𝑥))
30	29	ralsng 4639	. . . . . . . 8 ⊢ (𝐵 ∈ On → (∀𝑡 ∈ {𝐵} (𝑧 +no 𝑡) ∈ 𝑥 ↔ (𝑧 +no 𝐵) ∈ 𝑥))
31	30	ralbidv 3156	. . . . . . 7 ⊢ (𝐵 ∈ On → (∀𝑧 ∈ 𝐴 ∀𝑡 ∈ {𝐵} (𝑧 +no 𝑡) ∈ 𝑥 ↔ ∀𝑧 ∈ 𝐴 (𝑧 +no 𝐵) ∈ 𝑥))
32	31	adantl 481	. . . . . 6 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (∀𝑧 ∈ 𝐴 ∀𝑡 ∈ {𝐵} (𝑧 +no 𝑡) ∈ 𝑥 ↔ ∀𝑧 ∈ 𝐴 (𝑧 +no 𝐵) ∈ 𝑥))
33	27, 32	bitrd 279	. . . . 5 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (( +no “ (𝐴 × {𝐵})) ⊆ 𝑥 ↔ ∀𝑧 ∈ 𝐴 (𝑧 +no 𝐵) ∈ 𝑥))
34	19, 33	anbi12d 632	. . . 4 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ((( +no “ ({𝐴} × 𝐵)) ⊆ 𝑥 ∧ ( +no “ (𝐴 × {𝐵})) ⊆ 𝑥) ↔ (∀𝑦 ∈ 𝐵 (𝐴 +no 𝑦) ∈ 𝑥 ∧ ∀𝑧 ∈ 𝐴 (𝑧 +no 𝐵) ∈ 𝑥)))
35	34	rabbidv 3413	. . 3 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → {𝑥 ∈ On ∣ (( +no “ ({𝐴} × 𝐵)) ⊆ 𝑥 ∧ ( +no “ (𝐴 × {𝐵})) ⊆ 𝑥)} = {𝑥 ∈ On ∣ (∀𝑦 ∈ 𝐵 (𝐴 +no 𝑦) ∈ 𝑥 ∧ ∀𝑧 ∈ 𝐴 (𝑧 +no 𝐵) ∈ 𝑥)})
36	35	inteqd 4915	. 2 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ∩ {𝑥 ∈ On ∣ (( +no “ ({𝐴} × 𝐵)) ⊆ 𝑥 ∧ ( +no “ (𝐴 × {𝐵})) ⊆ 𝑥)} = ∩ {𝑥 ∈ On ∣ (∀𝑦 ∈ 𝐵 (𝐴 +no 𝑦) ∈ 𝑥 ∧ ∀𝑧 ∈ 𝐴 (𝑧 +no 𝐵) ∈ 𝑥)})
37	1, 36	eqtrd 2764	1 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +no 𝐵) = ∩ {𝑥 ∈ On ∣ (∀𝑦 ∈ 𝐵 (𝐴 +no 𝑦) ∈ 𝑥 ∧ ∀𝑧 ∈ 𝐴 (𝑧 +no 𝐵) ∈ 𝑥)})

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395   = wceq 1540   ∈ wcel 2109  ∀wral 3044  {crab 3405   ⊆ wss 3914  {csn 4589  ∩ cint 4910   × cxp 5636  dom cdm 5638   “ cima 5641  Oncon0 6332  Fun wfun 6505   Fn wfn 6506  (class class class)co 7387   +no cnadd 8629

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-8 2111  ax-9 2119  ax-10 2142  ax-11 2158  ax-12 2178  ax-ext 2701  ax-rep 5234  ax-sep 5251  ax-nul 5261  ax-pow 5320  ax-pr 5387  ax-un 7711

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3or 1087  df-3an 1088  df-tru 1543  df-fal 1553  df-ex 1780  df-nf 1784  df-sb 2066  df-mo 2533  df-eu 2562  df-clab 2708  df-cleq 2721  df-clel 2803  df-nfc 2878  df-ne 2926  df-ral 3045  df-rex 3054  df-reu 3355  df-rab 3406  df-v 3449  df-sbc 3754  df-csb 3863  df-dif 3917  df-un 3919  df-in 3921  df-ss 3931  df-pss 3934  df-nul 4297  df-if 4489  df-pw 4565  df-sn 4590  df-pr 4592  df-op 4596  df-uni 4872  df-int 4911  df-iun 4957  df-br 5108  df-opab 5170  df-mpt 5189  df-tr 5215  df-id 5533  df-eprel 5538  df-po 5546  df-so 5547  df-fr 5591  df-se 5592  df-we 5593  df-xp 5644  df-rel 5645  df-cnv 5646  df-co 5647  df-dm 5648  df-rn 5649  df-res 5650  df-ima 5651  df-pred 6274  df-ord 6335  df-on 6336  df-suc 6338  df-iota 6464  df-fun 6513  df-fn 6514  df-f 6515  df-f1 6516  df-fo 6517  df-f1o 6518  df-fv 6519  df-ov 7390  df-oprab 7391  df-mpo 7392  df-1st 7968  df-2nd 7969  df-frecs 8260  df-nadd 8630

This theorem is referenced by:  naddcom  8646  naddrid  8647  naddssim  8649  naddelim  8650  naddsuc2  8665  naddov4  43372  nadd1suc  43381