Theorem onomeneq 8992

Description: An ordinal number equinumerous to a natural number is equal to it. Proposition 10.22 of [TakeutiZaring] p. 90 and its converse. (Contributed by NM, 26-Jul-2004.)

Assertion

Ref	Expression
onomeneq	⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → (𝐴 ≈ 𝐵 ↔ 𝐴 = 𝐵))

Proof of Theorem onomeneq

Step	Hyp	Ref	Expression
1		php5 8978	. . . . . . . . 9 ⊢ (𝐵 ∈ ω → ¬ 𝐵 ≈ suc 𝐵)
2	1	ad2antlr 724	. . . . . . . 8 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → ¬ 𝐵 ≈ suc 𝐵)
3		enen1 8886	. . . . . . . . 9 ⊢ (𝐴 ≈ 𝐵 → (𝐴 ≈ suc 𝐵 ↔ 𝐵 ≈ suc 𝐵))
4	3	adantl 482	. . . . . . . 8 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → (𝐴 ≈ suc 𝐵 ↔ 𝐵 ≈ suc 𝐵))
5	2, 4	mtbird 325	. . . . . . 7 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → ¬ 𝐴 ≈ suc 𝐵)
6		peano2 7731	. . . . . . . . . . . . . 14 ⊢ (𝐵 ∈ ω → suc 𝐵 ∈ ω)
7		sssucid 6342	. . . . . . . . . . . . . 14 ⊢ 𝐵 ⊆ suc 𝐵
8		ssdomg 8769	. . . . . . . . . . . . . 14 ⊢ (suc 𝐵 ∈ ω → (𝐵 ⊆ suc 𝐵 → 𝐵 ≼ suc 𝐵))
9	6, 7, 8	mpisyl 21	. . . . . . . . . . . . 13 ⊢ (𝐵 ∈ ω → 𝐵 ≼ suc 𝐵)
10		endomtr 8781	. . . . . . . . . . . . 13 ⊢ ((𝐴 ≈ 𝐵 ∧ 𝐵 ≼ suc 𝐵) → 𝐴 ≼ suc 𝐵)
11	9, 10	sylan2 593	. . . . . . . . . . . 12 ⊢ ((𝐴 ≈ 𝐵 ∧ 𝐵 ∈ ω) → 𝐴 ≼ suc 𝐵)
12	11	ancoms 459	. . . . . . . . . . 11 ⊢ ((𝐵 ∈ ω ∧ 𝐴 ≈ 𝐵) → 𝐴 ≼ suc 𝐵)
13	12	a1d 25	. . . . . . . . . 10 ⊢ ((𝐵 ∈ ω ∧ 𝐴 ≈ 𝐵) → (ω ⊆ 𝐴 → 𝐴 ≼ suc 𝐵))
14	13	adantll 711	. . . . . . . . 9 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → (ω ⊆ 𝐴 → 𝐴 ≼ suc 𝐵))
15		ssel 3919	. . . . . . . . . . . . . . 15 ⊢ (ω ⊆ 𝐴 → (𝐵 ∈ ω → 𝐵 ∈ 𝐴))
16	15	com12 32	. . . . . . . . . . . . . 14 ⊢ (𝐵 ∈ ω → (ω ⊆ 𝐴 → 𝐵 ∈ 𝐴))
17	16	adantr 481	. . . . . . . . . . . . 13 ⊢ ((𝐵 ∈ ω ∧ 𝐴 ∈ On) → (ω ⊆ 𝐴 → 𝐵 ∈ 𝐴))
18		eloni 6275	. . . . . . . . . . . . . 14 ⊢ (𝐴 ∈ On → Ord 𝐴)
19		ordelsuc 7661	. . . . . . . . . . . . . 14 ⊢ ((𝐵 ∈ ω ∧ Ord 𝐴) → (𝐵 ∈ 𝐴 ↔ suc 𝐵 ⊆ 𝐴))
20	18, 19	sylan2 593	. . . . . . . . . . . . 13 ⊢ ((𝐵 ∈ ω ∧ 𝐴 ∈ On) → (𝐵 ∈ 𝐴 ↔ suc 𝐵 ⊆ 𝐴))
21	17, 20	sylibd 238	. . . . . . . . . . . 12 ⊢ ((𝐵 ∈ ω ∧ 𝐴 ∈ On) → (ω ⊆ 𝐴 → suc 𝐵 ⊆ 𝐴))
22		ssdomg 8769	. . . . . . . . . . . . 13 ⊢ (𝐴 ∈ On → (suc 𝐵 ⊆ 𝐴 → suc 𝐵 ≼ 𝐴))
23	22	adantl 482	. . . . . . . . . . . 12 ⊢ ((𝐵 ∈ ω ∧ 𝐴 ∈ On) → (suc 𝐵 ⊆ 𝐴 → suc 𝐵 ≼ 𝐴))
24	21, 23	syld 47	. . . . . . . . . . 11 ⊢ ((𝐵 ∈ ω ∧ 𝐴 ∈ On) → (ω ⊆ 𝐴 → suc 𝐵 ≼ 𝐴))
25	24	ancoms 459	. . . . . . . . . 10 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → (ω ⊆ 𝐴 → suc 𝐵 ≼ 𝐴))
26	25	adantr 481	. . . . . . . . 9 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → (ω ⊆ 𝐴 → suc 𝐵 ≼ 𝐴))
27	14, 26	jcad 513	. . . . . . . 8 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → (ω ⊆ 𝐴 → (𝐴 ≼ suc 𝐵 ∧ suc 𝐵 ≼ 𝐴)))
28		sbth 8862	. . . . . . . 8 ⊢ ((𝐴 ≼ suc 𝐵 ∧ suc 𝐵 ≼ 𝐴) → 𝐴 ≈ suc 𝐵)
29	27, 28	syl6 35	. . . . . . 7 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → (ω ⊆ 𝐴 → 𝐴 ≈ suc 𝐵))
30	5, 29	mtod 197	. . . . . 6 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → ¬ ω ⊆ 𝐴)
31		ordom 7716	. . . . . . . . 9 ⊢ Ord ω
32		ordtri1 6298	. . . . . . . . 9 ⊢ ((Ord ω ∧ Ord 𝐴) → (ω ⊆ 𝐴 ↔ ¬ 𝐴 ∈ ω))
33	31, 18, 32	sylancr 587	. . . . . . . 8 ⊢ (𝐴 ∈ On → (ω ⊆ 𝐴 ↔ ¬ 𝐴 ∈ ω))
34	33	con2bid 355	. . . . . . 7 ⊢ (𝐴 ∈ On → (𝐴 ∈ ω ↔ ¬ ω ⊆ 𝐴))
35	34	ad2antrr 723	. . . . . 6 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → (𝐴 ∈ ω ↔ ¬ ω ⊆ 𝐴))
36	30, 35	mpbird 256	. . . . 5 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → 𝐴 ∈ ω)
37		simplr 766	. . . . 5 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → 𝐵 ∈ ω)
38	36, 37	jca 512	. . . 4 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → (𝐴 ∈ ω ∧ 𝐵 ∈ ω))
39		nneneq 8973	. . . . 5 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ≈ 𝐵 ↔ 𝐴 = 𝐵))
40	39	biimpa 477	. . . 4 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → 𝐴 = 𝐵)
41	38, 40	sylancom 588	. . 3 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ ω) ∧ 𝐴 ≈ 𝐵) → 𝐴 = 𝐵)
42	41	ex 413	. 2 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → (𝐴 ≈ 𝐵 → 𝐴 = 𝐵))
43		eqeng 8757	. . 3 ⊢ (𝐴 ∈ On → (𝐴 = 𝐵 → 𝐴 ≈ 𝐵))
44	43	adantr 481	. 2 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → (𝐴 = 𝐵 → 𝐴 ≈ 𝐵))
45	42, 44	impbid 211	1 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → (𝐴 ≈ 𝐵 ↔ 𝐴 = 𝐵))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 205   ∧ wa 396   = wceq 1542   ∈ wcel 2110   ⊆ wss 3892   class class class wbr 5079  Ord word 6264  Oncon0 6265  suc csuc 6267  ωcom 7706   ≈ cen 8713   ≼ cdom 8714

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1802  ax-4 1816  ax-5 1917  ax-6 1975  ax-7 2015  ax-8 2112  ax-9 2120  ax-10 2141  ax-11 2158  ax-12 2175  ax-ext 2711  ax-sep 5227  ax-nul 5234  ax-pow 5292  ax-pr 5356  ax-un 7582

This theorem depends on definitions:  df-bi 206  df-an 397  df-or 845  df-3or 1087  df-3an 1088  df-tru 1545  df-fal 1555  df-ex 1787  df-nf 1791  df-sb 2072  df-mo 2542  df-eu 2571  df-clab 2718  df-cleq 2732  df-clel 2818  df-nfc 2891  df-ne 2946  df-ral 3071  df-rex 3072  df-reu 3073  df-rab 3075  df-v 3433  df-sbc 3721  df-csb 3838  df-dif 3895  df-un 3897  df-in 3899  df-ss 3909  df-pss 3911  df-nul 4263  df-if 4466  df-pw 4541  df-sn 4568  df-pr 4570  df-op 4574  df-uni 4846  df-br 5080  df-opab 5142  df-mpt 5163  df-tr 5197  df-id 5490  df-eprel 5496  df-po 5504  df-so 5505  df-fr 5545  df-we 5547  df-xp 5596  df-rel 5597  df-cnv 5598  df-co 5599  df-dm 5600  df-rn 5601  df-res 5602  df-ima 5603  df-ord 6268  df-on 6269  df-lim 6270  df-suc 6271  df-iota 6390  df-fun 6434  df-fn 6435  df-f 6436  df-f1 6437  df-fo 6438  df-f1o 6439  df-fv 6440  df-om 7707  df-1o 8288  df-er 8481  df-en 8717  df-dom 8718  df-sdom 8719  df-fin 8720

This theorem is referenced by:  onfin  8993  ficardom  9720  finnisoeu  9870