Theorem ondomon 10522

Description: The class of ordinals dominated by a given set is an ordinal. Theorem 56 of [Suppes] p. 227. This theorem can be proved without the axiom of choice, see hartogs 9494. (Contributed by NM, 7-Nov-2003.) (Proof modification is discouraged.) Use hartogs 9494 instead. (New usage is discouraged.)

Assertion

Ref	Expression
ondomon	⊢ (𝐴 ∈ 𝑉 → {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ∈ On)

Distinct variable group:   𝑥,𝐴

Allowed substitution hint:   𝑉(𝑥)

Proof of Theorem ondomon

Dummy variables 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		onelon 6373	. . . . . . . . . . . 12 ⊢ ((𝑧 ∈ On ∧ 𝑦 ∈ 𝑧) → 𝑦 ∈ On)
2		vex 3460	. . . . . . . . . . . . 13 ⊢ 𝑧 ∈ V
3		onelss 6390	. . . . . . . . . . . . . 14 ⊢ (𝑧 ∈ On → (𝑦 ∈ 𝑧 → 𝑦 ⊆ 𝑧))
4	3	imp 410	. . . . . . . . . . . . 13 ⊢ ((𝑧 ∈ On ∧ 𝑦 ∈ 𝑧) → 𝑦 ⊆ 𝑧)
5		ssdomg 8983	. . . . . . . . . . . . 13 ⊢ (𝑧 ∈ V → (𝑦 ⊆ 𝑧 → 𝑦 ≼ 𝑧))
6	2, 4, 5	mpsyl 68	. . . . . . . . . . . 12 ⊢ ((𝑧 ∈ On ∧ 𝑦 ∈ 𝑧) → 𝑦 ≼ 𝑧)
7	1, 6	jca 519	. . . . . . . . . . 11 ⊢ ((𝑧 ∈ On ∧ 𝑦 ∈ 𝑧) → (𝑦 ∈ On ∧ 𝑦 ≼ 𝑧))
8		domtr 8990	. . . . . . . . . . . . 13 ⊢ ((𝑦 ≼ 𝑧 ∧ 𝑧 ≼ 𝐴) → 𝑦 ≼ 𝐴)
9	8	anim2i 626	. . . . . . . . . . . 12 ⊢ ((𝑦 ∈ On ∧ (𝑦 ≼ 𝑧 ∧ 𝑧 ≼ 𝐴)) → (𝑦 ∈ On ∧ 𝑦 ≼ 𝐴))
10	9	anassrs 471	. . . . . . . . . . 11 ⊢ (((𝑦 ∈ On ∧ 𝑦 ≼ 𝑧) ∧ 𝑧 ≼ 𝐴) → (𝑦 ∈ On ∧ 𝑦 ≼ 𝐴))
11	7, 10	sylan 589	. . . . . . . . . 10 ⊢ (((𝑧 ∈ On ∧ 𝑦 ∈ 𝑧) ∧ 𝑧 ≼ 𝐴) → (𝑦 ∈ On ∧ 𝑦 ≼ 𝐴))
12	11	exp31 423	. . . . . . . . 9 ⊢ (𝑧 ∈ On → (𝑦 ∈ 𝑧 → (𝑧 ≼ 𝐴 → (𝑦 ∈ On ∧ 𝑦 ≼ 𝐴))))
13	12	com12 32	. . . . . . . 8 ⊢ (𝑦 ∈ 𝑧 → (𝑧 ∈ On → (𝑧 ≼ 𝐴 → (𝑦 ∈ On ∧ 𝑦 ≼ 𝐴))))
14	13	impd 414	. . . . . . 7 ⊢ (𝑦 ∈ 𝑧 → ((𝑧 ∈ On ∧ 𝑧 ≼ 𝐴) → (𝑦 ∈ On ∧ 𝑦 ≼ 𝐴)))
15		breq1 5105	. . . . . . . 8 ⊢ (𝑥 = 𝑧 → (𝑥 ≼ 𝐴 ↔ 𝑧 ≼ 𝐴))
16	15	elrab 3652	. . . . . . 7 ⊢ (𝑧 ∈ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ↔ (𝑧 ∈ On ∧ 𝑧 ≼ 𝐴))
17		breq1 5105	. . . . . . . 8 ⊢ (𝑥 = 𝑦 → (𝑥 ≼ 𝐴 ↔ 𝑦 ≼ 𝐴))
18	17	elrab 3652	. . . . . . 7 ⊢ (𝑦 ∈ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ↔ (𝑦 ∈ On ∧ 𝑦 ≼ 𝐴))
19	14, 16, 18	3imtr4g 298	. . . . . 6 ⊢ (𝑦 ∈ 𝑧 → (𝑧 ∈ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} → 𝑦 ∈ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴}))
20	19	imp 410	. . . . 5 ⊢ ((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴}) → 𝑦 ∈ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴})
21	20	gen2 1818	. . . 4 ⊢ ∀𝑦∀𝑧((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴}) → 𝑦 ∈ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴})
22		dftr2 5211	. . . 4 ⊢ (Tr {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ↔ ∀𝑦∀𝑧((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴}) → 𝑦 ∈ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴}))
23	21, 22	mpbir 233	. . 3 ⊢ Tr {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴}
24		ssrab2 4035	. . 3 ⊢ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ⊆ On
25		ordon 7762	. . 3 ⊢ Ord On
26		trssord 6365	. . 3 ⊢ ((Tr {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ∧ {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ⊆ On ∧ Ord On) → Ord {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴})
27	23, 24, 25, 26	mp3an 1484	. 2 ⊢ Ord {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴}
28		pwexg 5337	. . . . . 6 ⊢ (𝐴 ∈ 𝑉 → 𝒫 𝐴 ∈ V)
29		numth3 10429	. . . . . 6 ⊢ (𝒫 𝐴 ∈ V → 𝒫 𝐴 ∈ dom card)
30		cardval2 9951	. . . . . 6 ⊢ (𝒫 𝐴 ∈ dom card → (card‘𝒫 𝐴) = {𝑥 ∈ On ∣ 𝑥 ≺ 𝒫 𝐴})
31	28, 29, 30	3syl 18	. . . . 5 ⊢ (𝐴 ∈ 𝑉 → (card‘𝒫 𝐴) = {𝑥 ∈ On ∣ 𝑥 ≺ 𝒫 𝐴})
32		fvex 6882	. . . . 5 ⊢ (card‘𝒫 𝐴) ∈ V
33	31, 32	eqeltrrdi 2873	. . . 4 ⊢ (𝐴 ∈ 𝑉 → {𝑥 ∈ On ∣ 𝑥 ≺ 𝒫 𝐴} ∈ V)
34		elex 3477	. . . . . 6 ⊢ (𝐴 ∈ 𝑉 → 𝐴 ∈ V)
35		canth2g 9105	. . . . . . . . 9 ⊢ (𝐴 ∈ V → 𝐴 ≺ 𝒫 𝐴)
36		domsdomtr 9086	. . . . . . . . 9 ⊢ ((𝑥 ≼ 𝐴 ∧ 𝐴 ≺ 𝒫 𝐴) → 𝑥 ≺ 𝒫 𝐴)
37	35, 36	sylan2 602	. . . . . . . 8 ⊢ ((𝑥 ≼ 𝐴 ∧ 𝐴 ∈ V) → 𝑥 ≺ 𝒫 𝐴)
38	37	expcom 417	. . . . . . 7 ⊢ (𝐴 ∈ V → (𝑥 ≼ 𝐴 → 𝑥 ≺ 𝒫 𝐴))
39	38	ralrimivw 3160	. . . . . 6 ⊢ (𝐴 ∈ V → ∀𝑥 ∈ On (𝑥 ≼ 𝐴 → 𝑥 ≺ 𝒫 𝐴))
40	34, 39	syl 17	. . . . 5 ⊢ (𝐴 ∈ 𝑉 → ∀𝑥 ∈ On (𝑥 ≼ 𝐴 → 𝑥 ≺ 𝒫 𝐴))
41	40	ss2rabd 4027	. . . 4 ⊢ (𝐴 ∈ 𝑉 → {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ⊆ {𝑥 ∈ On ∣ 𝑥 ≺ 𝒫 𝐴})
42	33, 41	ssexd 5282	. . 3 ⊢ (𝐴 ∈ 𝑉 → {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ∈ V)
43		elong 6356	. . 3 ⊢ ({𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ∈ V → ({𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ∈ On ↔ Ord {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴}))
44	42, 43	syl 17	. 2 ⊢ (𝐴 ∈ 𝑉 → ({𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ∈ On ↔ Ord {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴}))
45	27, 44	mpbiri 260	1 ⊢ (𝐴 ∈ 𝑉 → {𝑥 ∈ On ∣ 𝑥 ≼ 𝐴} ∈ On)

Syntax hints:   → wi 4   ↔ wb 208   ∧ wa 399  ∀wal 1560   = wceq 1562   ∈ wcel 2144  ∀wral 3078  {crab 3416  Vcvv 3456   ⊆ wss 3906  𝒫 cpw 4557   class class class wbr 5102  Tr wtr 5209  dom cdm 5649  Ord word 6347  Oncon0 6348  ‘cfv 6523   ≼ cdom 8927   ≺ csdm 8928  cardccrd 9895

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1817  ax-4 1831  ax-5 1932  ax-6 1989  ax-7 2030  ax-8 2146  ax-9 2154  ax-10 2177  ax-11 2193  ax-12 2214  ax-ext 2736  ax-rep 5229  ax-sep 5248  ax-nul 5258  ax-pow 5324  ax-pr 5392  ax-un 7720  ax-ac2 10422

This theorem depends on definitions:  df-bi 209  df-an 400  df-or 859  df-3or 1100  df-3an 1101  df-tru 1565  df-fal 1575  df-ex 1802  df-nf 1806  df-sb 2093  df-mo 2568  df-eu 2598  df-clab 2743  df-cleq 2756  df-clel 2839  df-nfc 2913  df-ne 2960  df-ral 3079  df-rex 3089  df-rmo 3369  df-reu 3370  df-rab 3417  df-v 3458  df-sbc 3747  df-csb 3855  df-dif 3909  df-un 3911  df-in 3913  df-ss 3923  df-pss 3926  df-nul 4288  df-if 4483  df-pw 4559  df-sn 4585  df-pr 4587  df-op 4591  df-uni 4868  df-int 4908  df-iun 4953  df-br 5103  df-opab 5165  df-mpt 5184  df-tr 5210  df-id 5544  df-eprel 5549  df-po 5557  df-so 5558  df-fr 5602  df-se 5603  df-we 5604  df-xp 5655  df-rel 5656  df-cnv 5657  df-co 5658  df-dm 5659  df-rn 5660  df-res 5661  df-ima 5662  df-pred 6290  df-ord 6351  df-on 6352  df-suc 6354  df-iota 6479  df-fun 6525  df-fn 6526  df-f 6527  df-f1 6528  df-fo 6529  df-f1o 6530  df-fv 6531  df-isom 6532  df-riota 7355  df-ov 7401  df-2nd 7973  df-frecs 8264  df-wrecs 8295  df-recs 8344  df-er 8680  df-en 8930  df-dom 8931  df-sdom 8932  df-card 9899  df-ac 10074

This theorem is referenced by: (None)