Theorem tz7.7 6387

Description: A transitive class belongs to an ordinal class iff it is strictly included in it. Proposition 7.7 of [TakeutiZaring] p. 37. (Contributed by NM, 5-May-1994.)

Assertion

Ref	Expression
tz7.7	⊢ ((Ord 𝐴 ∧ Tr 𝐵) → (𝐵 ∈ 𝐴 ↔ (𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ 𝐴)))

Proof of Theorem tz7.7

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

Step	Hyp	Ref	Expression
1		ordtr 6375	. . . 4 ⊢ (Ord 𝐴 → Tr 𝐴)
2		ordfr 6376	. . . 4 ⊢ (Ord 𝐴 → E Fr 𝐴)
3		tz7.2 5645	. . . . 5 ⊢ ((Tr 𝐴 ∧ E Fr 𝐴 ∧ 𝐵 ∈ 𝐴) → (𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ 𝐴))
4	3	3exp 1135	. . . 4 ⊢ (Tr 𝐴 → ( E Fr 𝐴 → (𝐵 ∈ 𝐴 → (𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ 𝐴))))
5	1, 2, 4	sylc 66	. . 3 ⊢ (Ord 𝐴 → (𝐵 ∈ 𝐴 → (𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ 𝐴)))
6	5	adantr 485	. 2 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → (𝐵 ∈ 𝐴 → (𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ 𝐴)))
7		pssdifn0 4331	. . . . . 6 ⊢ ((𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ 𝐴) → (𝐴 ∖ 𝐵) ≠ ∅)
8		difss 4098	. . . . . . . . . . . 12 ⊢ (𝐴 ∖ 𝐵) ⊆ 𝐴
9		tz7.5 6382	. . . . . . . . . . . 12 ⊢ ((Ord 𝐴 ∧ (𝐴 ∖ 𝐵) ⊆ 𝐴 ∧ (𝐴 ∖ 𝐵) ≠ ∅) → ∃𝑥 ∈ (𝐴 ∖ 𝐵)((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅)
10	8, 9	mp3an2 1475	. . . . . . . . . . 11 ⊢ ((Ord 𝐴 ∧ (𝐴 ∖ 𝐵) ≠ ∅) → ∃𝑥 ∈ (𝐴 ∖ 𝐵)((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅)
11		eldifi 4093	. . . . . . . . . . . . . . . . . 18 ⊢ (𝑥 ∈ (𝐴 ∖ 𝐵) → 𝑥 ∈ 𝐴)
12		trss 5232	. . . . . . . . . . . . . . . . . 18 ⊢ (Tr 𝐴 → (𝑥 ∈ 𝐴 → 𝑥 ⊆ 𝐴))
13		difin0ss 4336	. . . . . . . . . . . . . . . . . . 19 ⊢ (((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅ → (𝑥 ⊆ 𝐴 → 𝑥 ⊆ 𝐵))
14	13	com12 33	. . . . . . . . . . . . . . . . . 18 ⊢ (𝑥 ⊆ 𝐴 → (((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅ → 𝑥 ⊆ 𝐵))
15	11, 12, 14	syl56 37	. . . . . . . . . . . . . . . . 17 ⊢ (Tr 𝐴 → (𝑥 ∈ (𝐴 ∖ 𝐵) → (((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅ → 𝑥 ⊆ 𝐵)))
16	1, 15	syl 18	. . . . . . . . . . . . . . . 16 ⊢ (Ord 𝐴 → (𝑥 ∈ (𝐴 ∖ 𝐵) → (((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅ → 𝑥 ⊆ 𝐵)))
17	16	ad2antrr 738	. . . . . . . . . . . . . . 15 ⊢ (((Ord 𝐴 ∧ Tr 𝐵) ∧ 𝐵 ⊆ 𝐴) → (𝑥 ∈ (𝐴 ∖ 𝐵) → (((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅ → 𝑥 ⊆ 𝐵)))
18	17	imp32 423	. . . . . . . . . . . . . 14 ⊢ ((((Ord 𝐴 ∧ Tr 𝐵) ∧ 𝐵 ⊆ 𝐴) ∧ (𝑥 ∈ (𝐴 ∖ 𝐵) ∧ ((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅)) → 𝑥 ⊆ 𝐵)
19		eleq1w 2852	. . . . . . . . . . . . . . . . . . . . . . . . 25 ⊢ (𝑦 = 𝑥 → (𝑦 ∈ 𝐵 ↔ 𝑥 ∈ 𝐵))
20	19	biimpcd 252	. . . . . . . . . . . . . . . . . . . . . . . 24 ⊢ (𝑦 ∈ 𝐵 → (𝑦 = 𝑥 → 𝑥 ∈ 𝐵))
21		eldifn 4094	. . . . . . . . . . . . . . . . . . . . . . . 24 ⊢ (𝑥 ∈ (𝐴 ∖ 𝐵) → ¬ 𝑥 ∈ 𝐵)
22	20, 21	nsyli 158	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (𝑦 ∈ 𝐵 → (𝑥 ∈ (𝐴 ∖ 𝐵) → ¬ 𝑦 = 𝑥))
23	22	imp 411	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ ((𝑦 ∈ 𝐵 ∧ 𝑥 ∈ (𝐴 ∖ 𝐵)) → ¬ 𝑦 = 𝑥)
24	23	adantll 726	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (((𝐵 ⊆ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑥 ∈ (𝐴 ∖ 𝐵)) → ¬ 𝑦 = 𝑥)
25	24	adantl 486	. . . . . . . . . . . . . . . . . . . 20 ⊢ (((Ord 𝐴 ∧ Tr 𝐵) ∧ ((𝐵 ⊆ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑥 ∈ (𝐴 ∖ 𝐵))) → ¬ 𝑦 = 𝑥)
26		trel 5230	. . . . . . . . . . . . . . . . . . . . . . . . . . 27 ⊢ (Tr 𝐵 → ((𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵) → 𝑥 ∈ 𝐵))
27	26	expcomd 421	. . . . . . . . . . . . . . . . . . . . . . . . . 26 ⊢ (Tr 𝐵 → (𝑦 ∈ 𝐵 → (𝑥 ∈ 𝑦 → 𝑥 ∈ 𝐵)))
28	27	imp 411	. . . . . . . . . . . . . . . . . . . . . . . . 25 ⊢ ((Tr 𝐵 ∧ 𝑦 ∈ 𝐵) → (𝑥 ∈ 𝑦 → 𝑥 ∈ 𝐵))
29	28, 21	nsyli 158	. . . . . . . . . . . . . . . . . . . . . . . 24 ⊢ ((Tr 𝐵 ∧ 𝑦 ∈ 𝐵) → (𝑥 ∈ (𝐴 ∖ 𝐵) → ¬ 𝑥 ∈ 𝑦))
30	29	ex 417	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (Tr 𝐵 → (𝑦 ∈ 𝐵 → (𝑥 ∈ (𝐴 ∖ 𝐵) → ¬ 𝑥 ∈ 𝑦)))
31	30	adantld 495	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (Tr 𝐵 → ((𝐵 ⊆ 𝐴 ∧ 𝑦 ∈ 𝐵) → (𝑥 ∈ (𝐴 ∖ 𝐵) → ¬ 𝑥 ∈ 𝑦)))
32	31	imp32 423	. . . . . . . . . . . . . . . . . . . . 21 ⊢ ((Tr 𝐵 ∧ ((𝐵 ⊆ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑥 ∈ (𝐴 ∖ 𝐵))) → ¬ 𝑥 ∈ 𝑦)
33	32	adantll 726	. . . . . . . . . . . . . . . . . . . 20 ⊢ (((Ord 𝐴 ∧ Tr 𝐵) ∧ ((𝐵 ⊆ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑥 ∈ (𝐴 ∖ 𝐵))) → ¬ 𝑥 ∈ 𝑦)
34		ordwe 6374	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (Ord 𝐴 → E We 𝐴)
35		ssel2 3940	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ ((𝐵 ⊆ 𝐴 ∧ 𝑦 ∈ 𝐵) → 𝑦 ∈ 𝐴)
36	35, 11	anim12i 624	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (((𝐵 ⊆ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑥 ∈ (𝐴 ∖ 𝐵)) → (𝑦 ∈ 𝐴 ∧ 𝑥 ∈ 𝐴))
37		wecmpep 5654	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (( E We 𝐴 ∧ (𝑦 ∈ 𝐴 ∧ 𝑥 ∈ 𝐴)) → (𝑦 ∈ 𝑥 ∨ 𝑦 = 𝑥 ∨ 𝑥 ∈ 𝑦))
38	34, 36, 37	syl2an 607	. . . . . . . . . . . . . . . . . . . . 21 ⊢ ((Ord 𝐴 ∧ ((𝐵 ⊆ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑥 ∈ (𝐴 ∖ 𝐵))) → (𝑦 ∈ 𝑥 ∨ 𝑦 = 𝑥 ∨ 𝑥 ∈ 𝑦))
39	38	adantlr 727	. . . . . . . . . . . . . . . . . . . 20 ⊢ (((Ord 𝐴 ∧ Tr 𝐵) ∧ ((𝐵 ⊆ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑥 ∈ (𝐴 ∖ 𝐵))) → (𝑦 ∈ 𝑥 ∨ 𝑦 = 𝑥 ∨ 𝑥 ∈ 𝑦))
40	25, 33, 39	ecase23d 1500	. . . . . . . . . . . . . . . . . . 19 ⊢ (((Ord 𝐴 ∧ Tr 𝐵) ∧ ((𝐵 ⊆ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑥 ∈ (𝐴 ∖ 𝐵))) → 𝑦 ∈ 𝑥)
41	40	exp44 442	. . . . . . . . . . . . . . . . . 18 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → (𝐵 ⊆ 𝐴 → (𝑦 ∈ 𝐵 → (𝑥 ∈ (𝐴 ∖ 𝐵) → 𝑦 ∈ 𝑥))))
42	41	com34 92	. . . . . . . . . . . . . . . . 17 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → (𝐵 ⊆ 𝐴 → (𝑥 ∈ (𝐴 ∖ 𝐵) → (𝑦 ∈ 𝐵 → 𝑦 ∈ 𝑥))))
43	42	imp31 422	. . . . . . . . . . . . . . . 16 ⊢ ((((Ord 𝐴 ∧ Tr 𝐵) ∧ 𝐵 ⊆ 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ 𝐵)) → (𝑦 ∈ 𝐵 → 𝑦 ∈ 𝑥))
44	43	ssrdv 3951	. . . . . . . . . . . . . . 15 ⊢ ((((Ord 𝐴 ∧ Tr 𝐵) ∧ 𝐵 ⊆ 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ 𝐵)) → 𝐵 ⊆ 𝑥)
45	44	adantrr 729	. . . . . . . . . . . . . 14 ⊢ ((((Ord 𝐴 ∧ Tr 𝐵) ∧ 𝐵 ⊆ 𝐴) ∧ (𝑥 ∈ (𝐴 ∖ 𝐵) ∧ ((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅)) → 𝐵 ⊆ 𝑥)
46	18, 45	eqssd 3962	. . . . . . . . . . . . 13 ⊢ ((((Ord 𝐴 ∧ Tr 𝐵) ∧ 𝐵 ⊆ 𝐴) ∧ (𝑥 ∈ (𝐴 ∖ 𝐵) ∧ ((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅)) → 𝑥 = 𝐵)
47	11	ad2antrl 740	. . . . . . . . . . . . 13 ⊢ ((((Ord 𝐴 ∧ Tr 𝐵) ∧ 𝐵 ⊆ 𝐴) ∧ (𝑥 ∈ (𝐴 ∖ 𝐵) ∧ ((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅)) → 𝑥 ∈ 𝐴)
48	46, 47	eqeltrrd 2870	. . . . . . . . . . . 12 ⊢ ((((Ord 𝐴 ∧ Tr 𝐵) ∧ 𝐵 ⊆ 𝐴) ∧ (𝑥 ∈ (𝐴 ∖ 𝐵) ∧ ((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅)) → 𝐵 ∈ 𝐴)
49	48	rexlimdvaa 3173	. . . . . . . . . . 11 ⊢ (((Ord 𝐴 ∧ Tr 𝐵) ∧ 𝐵 ⊆ 𝐴) → (∃𝑥 ∈ (𝐴 ∖ 𝐵)((𝐴 ∖ 𝐵) ∩ 𝑥) = ∅ → 𝐵 ∈ 𝐴))
50	10, 49	syl5 35	. . . . . . . . . 10 ⊢ (((Ord 𝐴 ∧ Tr 𝐵) ∧ 𝐵 ⊆ 𝐴) → ((Ord 𝐴 ∧ (𝐴 ∖ 𝐵) ≠ ∅) → 𝐵 ∈ 𝐴))
51	50	exp4b 435	. . . . . . . . 9 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → (𝐵 ⊆ 𝐴 → (Ord 𝐴 → ((𝐴 ∖ 𝐵) ≠ ∅ → 𝐵 ∈ 𝐴))))
52	51	com23 87	. . . . . . . 8 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → (Ord 𝐴 → (𝐵 ⊆ 𝐴 → ((𝐴 ∖ 𝐵) ≠ ∅ → 𝐵 ∈ 𝐴))))
53	52	adantrd 496	. . . . . . 7 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → ((Ord 𝐴 ∧ Tr 𝐵) → (𝐵 ⊆ 𝐴 → ((𝐴 ∖ 𝐵) ≠ ∅ → 𝐵 ∈ 𝐴))))
54	53	pm2.43i 53	. . . . . 6 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → (𝐵 ⊆ 𝐴 → ((𝐴 ∖ 𝐵) ≠ ∅ → 𝐵 ∈ 𝐴)))
55	7, 54	syl7 75	. . . . 5 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → (𝐵 ⊆ 𝐴 → ((𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ 𝐴) → 𝐵 ∈ 𝐴)))
56	55	exp4a 436	. . . 4 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → (𝐵 ⊆ 𝐴 → (𝐵 ⊆ 𝐴 → (𝐵 ≠ 𝐴 → 𝐵 ∈ 𝐴))))
57	56	pm2.43d 54	. . 3 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → (𝐵 ⊆ 𝐴 → (𝐵 ≠ 𝐴 → 𝐵 ∈ 𝐴)))
58	57	impd 415	. 2 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → ((𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ 𝐴) → 𝐵 ∈ 𝐴))
59	6, 58	impbid 215	1 ⊢ ((Ord 𝐴 ∧ Tr 𝐵) → (𝐵 ∈ 𝐴 ↔ (𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ 𝐴)))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 400   ∨ w3o 1100   = wceq 1567   ∈ wcel 2149   ≠ wne 2964  ∃wrex 3095   ∖ cdif 3910   ∩ cin 3912   ⊆ wss 3913  ∅c0 4294  Tr wtr 5222   E cep 5561   Fr wfr 5612   We wwe 5614  Ord word 6360

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1822  ax-4 1836  ax-5 1937  ax-6 1994  ax-7 2035  ax-8 2151  ax-9 2159  ax-ext 2741  ax-sep 5261  ax-pr 5405

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3or 1102  df-3an 1103  df-tru 1570  df-fal 1580  df-ex 1807  df-sb 2098  df-clab 2748  df-cleq 2761  df-clel 2844  df-ne 2965  df-ral 3086  df-rex 3096  df-rab 3424  df-v 3465  df-dif 3916  df-un 3918  df-in 3920  df-ss 3930  df-nul 4295  df-if 4493  df-pw 4569  df-sn 4595  df-pr 4597  df-op 4601  df-uni 4877  df-br 5114  df-opab 5178  df-tr 5223  df-eprel 5562  df-po 5570  df-so 5571  df-fr 5615  df-we 5617  df-ord 6364

This theorem is referenced by:  ordelssne  6388  dfon2  36180