Theorem nnawordex 8625

Description: Equivalence for weak ordering of natural numbers. (Contributed by NM, 8-Nov-2002.) (Revised by Mario Carneiro, 15-Nov-2014.)

Assertion

Ref	Expression
nnawordex	⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ⊆ 𝐵 ↔ ∃𝑥 ∈ ω (𝐴 +o 𝑥) = 𝐵))

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵

Proof of Theorem nnawordex

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		oveq2 7421	. . . . . . . 8 ⊢ (𝑦 = 𝐵 → (𝐴 +o 𝑦) = (𝐴 +o 𝐵))
2	1	sseq2d 3977	. . . . . . 7 ⊢ (𝑦 = 𝐵 → (𝐵 ⊆ (𝐴 +o 𝑦) ↔ 𝐵 ⊆ (𝐴 +o 𝐵)))
3		simplr 780	. . . . . . . 8 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → 𝐵 ∈ ω)
4		nnon 7870	. . . . . . . 8 ⊢ (𝐵 ∈ ω → 𝐵 ∈ On)
5	3, 4	syl 18	. . . . . . 7 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → 𝐵 ∈ On)
6		simpll 778	. . . . . . . 8 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → 𝐴 ∈ ω)
7		nnaword2 8618	. . . . . . . 8 ⊢ ((𝐵 ∈ ω ∧ 𝐴 ∈ ω) → 𝐵 ⊆ (𝐴 +o 𝐵))
8	3, 6, 7	syl2anc 595	. . . . . . 7 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → 𝐵 ⊆ (𝐴 +o 𝐵))
9	2, 5, 8	elrabd 3661	. . . . . 6 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → 𝐵 ∈ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)})
10		intss1 4932	. . . . . 6 ⊢ (𝐵 ∈ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} → ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ⊆ 𝐵)
11	9, 10	syl 18	. . . . 5 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ⊆ 𝐵)
12		ssrab2 4042	. . . . . . . 8 ⊢ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ⊆ On
13	9	ne0d 4303	. . . . . . . 8 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ≠ ∅)
14		oninton 7796	. . . . . . . 8 ⊢ (({𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ⊆ On ∧ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ≠ ∅) → ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ On)
15	12, 13, 14	sylancr 598	. . . . . . 7 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ On)
16		eloni 6373	. . . . . . 7 ⊢ (∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ On → Ord ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)})
17	15, 16	syl 18	. . . . . 6 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → Ord ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)})
18		ordom 7874	. . . . . 6 ⊢ Ord ω
19		ordtr2 6409	. . . . . 6 ⊢ ((Ord ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∧ Ord ω) → ((∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ⊆ 𝐵 ∧ 𝐵 ∈ ω) → ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ ω))
20	17, 18, 19	sylancl 597	. . . . 5 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → ((∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ⊆ 𝐵 ∧ 𝐵 ∈ ω) → ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ ω))
21	11, 3, 20	mp2and 711	. . . 4 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ ω)
22		nna0 8592	. . . . . . . . 9 ⊢ (𝐴 ∈ ω → (𝐴 +o ∅) = 𝐴)
23	22	ad2antrr 738	. . . . . . . 8 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → (𝐴 +o ∅) = 𝐴)
24		simpr 489	. . . . . . . 8 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → 𝐴 ⊆ 𝐵)
25	23, 24	eqsstrd 3979	. . . . . . 7 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → (𝐴 +o ∅) ⊆ 𝐵)
26		oveq2 7421	. . . . . . . 8 ⊢ (∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = ∅ → (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}) = (𝐴 +o ∅))
27	26	sseq1d 3976	. . . . . . 7 ⊢ (∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = ∅ → ((𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}) ⊆ 𝐵 ↔ (𝐴 +o ∅) ⊆ 𝐵))
28	25, 27	syl5ibrcom 250	. . . . . 6 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → (∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = ∅ → (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}) ⊆ 𝐵))
29		simprr 784	. . . . . . . . . 10 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)
30	29	oveq2d 7429	. . . . . . . . 9 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}) = (𝐴 +o suc 𝑥))
31	6	adantr 485	. . . . . . . . . 10 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → 𝐴 ∈ ω)
32		simprl 782	. . . . . . . . . 10 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → 𝑥 ∈ ω)
33		nnasuc 8594	. . . . . . . . . 10 ⊢ ((𝐴 ∈ ω ∧ 𝑥 ∈ ω) → (𝐴 +o suc 𝑥) = suc (𝐴 +o 𝑥))
34	31, 32, 33	syl2anc 595	. . . . . . . . 9 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → (𝐴 +o suc 𝑥) = suc (𝐴 +o 𝑥))
35	30, 34	eqtrd 2804	. . . . . . . 8 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}) = suc (𝐴 +o 𝑥))
36		nnord 7872	. . . . . . . . . . 11 ⊢ (𝐵 ∈ ω → Ord 𝐵)
37	3, 36	syl 18	. . . . . . . . . 10 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → Ord 𝐵)
38	37	adantr 485	. . . . . . . . 9 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → Ord 𝐵)
39		nnon 7870	. . . . . . . . . . . . 13 ⊢ (𝑥 ∈ ω → 𝑥 ∈ On)
40	39	adantr 485	. . . . . . . . . . . 12 ⊢ ((𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥) → 𝑥 ∈ On)
41		vex 3467	. . . . . . . . . . . . . 14 ⊢ 𝑥 ∈ V
42	41	sucid 6448	. . . . . . . . . . . . 13 ⊢ 𝑥 ∈ suc 𝑥
43		simpr 489	. . . . . . . . . . . . 13 ⊢ ((𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥) → ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)
44	42, 43	eleqtrrid 2876	. . . . . . . . . . . 12 ⊢ ((𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥) → 𝑥 ∈ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)})
45		oveq2 7421	. . . . . . . . . . . . . 14 ⊢ (𝑦 = 𝑥 → (𝐴 +o 𝑦) = (𝐴 +o 𝑥))
46	45	sseq2d 3977	. . . . . . . . . . . . 13 ⊢ (𝑦 = 𝑥 → (𝐵 ⊆ (𝐴 +o 𝑦) ↔ 𝐵 ⊆ (𝐴 +o 𝑥)))
47	46	onnminsb 7800	. . . . . . . . . . . 12 ⊢ (𝑥 ∈ On → (𝑥 ∈ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} → ¬ 𝐵 ⊆ (𝐴 +o 𝑥)))
48	40, 44, 47	sylc 66	. . . . . . . . . . 11 ⊢ ((𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥) → ¬ 𝐵 ⊆ (𝐴 +o 𝑥))
49	48	adantl 486	. . . . . . . . . 10 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → ¬ 𝐵 ⊆ (𝐴 +o 𝑥))
50		nnacl 8599	. . . . . . . . . . . . . 14 ⊢ ((𝐴 ∈ ω ∧ 𝑥 ∈ ω) → (𝐴 +o 𝑥) ∈ ω)
51	31, 32, 50	syl2anc 595	. . . . . . . . . . . . 13 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → (𝐴 +o 𝑥) ∈ ω)
52		nnord 7872	. . . . . . . . . . . . 13 ⊢ ((𝐴 +o 𝑥) ∈ ω → Ord (𝐴 +o 𝑥))
53	51, 52	syl 18	. . . . . . . . . . . 12 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → Ord (𝐴 +o 𝑥))
54		ordtri1 6397	. . . . . . . . . . . 12 ⊢ ((Ord 𝐵 ∧ Ord (𝐴 +o 𝑥)) → (𝐵 ⊆ (𝐴 +o 𝑥) ↔ ¬ (𝐴 +o 𝑥) ∈ 𝐵))
55	38, 53, 54	syl2anc 595	. . . . . . . . . . 11 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → (𝐵 ⊆ (𝐴 +o 𝑥) ↔ ¬ (𝐴 +o 𝑥) ∈ 𝐵))
56	55	con2bid 357	. . . . . . . . . 10 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → ((𝐴 +o 𝑥) ∈ 𝐵 ↔ ¬ 𝐵 ⊆ (𝐴 +o 𝑥)))
57	49, 56	mpbird 260	. . . . . . . . 9 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → (𝐴 +o 𝑥) ∈ 𝐵)
58		ordsucss 7816	. . . . . . . . 9 ⊢ (Ord 𝐵 → ((𝐴 +o 𝑥) ∈ 𝐵 → suc (𝐴 +o 𝑥) ⊆ 𝐵))
59	38, 57, 58	sylc 66	. . . . . . . 8 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → suc (𝐴 +o 𝑥) ⊆ 𝐵)
60	35, 59	eqsstrd 3979	. . . . . . 7 ⊢ ((((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) ∧ (𝑥 ∈ ω ∧ ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥)) → (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}) ⊆ 𝐵)
61	60	rexlimdvaa 3173	. . . . . 6 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → (∃𝑥 ∈ ω ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥 → (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}) ⊆ 𝐵))
62		nn0suc 7893	. . . . . . 7 ⊢ (∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ ω → (∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = ∅ ∨ ∃𝑥 ∈ ω ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥))
63	21, 62	syl 18	. . . . . 6 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → (∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = ∅ ∨ ∃𝑥 ∈ ω ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} = suc 𝑥))
64	28, 61, 63	mpjaod 873	. . . . 5 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}) ⊆ 𝐵)
65		onint 7791	. . . . . . 7 ⊢ (({𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ⊆ On ∧ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ≠ ∅) → ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)})
66	12, 13, 65	sylancr 598	. . . . . 6 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)})
67		nfrab1 3443	. . . . . . . . 9 ⊢ Ⅎ𝑦{𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}
68	67	nfint 4926	. . . . . . . 8 ⊢ Ⅎ𝑦∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}
69		nfcv 2931	. . . . . . . 8 ⊢ Ⅎ𝑦On
70		nfcv 2931	. . . . . . . . 9 ⊢ Ⅎ𝑦𝐵
71		nfcv 2931	. . . . . . . . . 10 ⊢ Ⅎ𝑦𝐴
72		nfcv 2931	. . . . . . . . . 10 ⊢ Ⅎ𝑦 +o
73	71, 72, 68	nfov 7443	. . . . . . . . 9 ⊢ Ⅎ𝑦(𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)})
74	70, 73	nfss 3938	. . . . . . . 8 ⊢ Ⅎ𝑦 𝐵 ⊆ (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)})
75		oveq2 7421	. . . . . . . . 9 ⊢ (𝑦 = ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} → (𝐴 +o 𝑦) = (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}))
76	75	sseq2d 3977	. . . . . . . 8 ⊢ (𝑦 = ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} → (𝐵 ⊆ (𝐴 +o 𝑦) ↔ 𝐵 ⊆ (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)})))
77	68, 69, 74, 76	elrabf 3656	. . . . . . 7 ⊢ (∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ↔ (∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ On ∧ 𝐵 ⊆ (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)})))
78	77	simprbi 502	. . . . . 6 ⊢ (∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} → 𝐵 ⊆ (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}))
79	66, 78	syl 18	. . . . 5 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → 𝐵 ⊆ (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}))
80	64, 79	eqssd 3962	. . . 4 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}) = 𝐵)
81		oveq2 7421	. . . . . 6 ⊢ (𝑥 = ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} → (𝐴 +o 𝑥) = (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}))
82	81	eqeq1d 2771	. . . . 5 ⊢ (𝑥 = ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} → ((𝐴 +o 𝑥) = 𝐵 ↔ (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}) = 𝐵))
83	82	rspcev 3590	. . . 4 ⊢ ((∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)} ∈ ω ∧ (𝐴 +o ∩ {𝑦 ∈ On ∣ 𝐵 ⊆ (𝐴 +o 𝑦)}) = 𝐵) → ∃𝑥 ∈ ω (𝐴 +o 𝑥) = 𝐵)
84	21, 80, 83	syl2anc 595	. . 3 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐴 ⊆ 𝐵) → ∃𝑥 ∈ ω (𝐴 +o 𝑥) = 𝐵)
85	84	ex 417	. 2 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ⊆ 𝐵 → ∃𝑥 ∈ ω (𝐴 +o 𝑥) = 𝐵))
86		nnaword1 8617	. . . . 5 ⊢ ((𝐴 ∈ ω ∧ 𝑥 ∈ ω) → 𝐴 ⊆ (𝐴 +o 𝑥))
87	86	adantlr 727	. . . 4 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝑥 ∈ ω) → 𝐴 ⊆ (𝐴 +o 𝑥))
88		sseq2 3971	. . . 4 ⊢ ((𝐴 +o 𝑥) = 𝐵 → (𝐴 ⊆ (𝐴 +o 𝑥) ↔ 𝐴 ⊆ 𝐵))
89	87, 88	syl5ibcom 248	. . 3 ⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝑥 ∈ ω) → ((𝐴 +o 𝑥) = 𝐵 → 𝐴 ⊆ 𝐵))
90	89	rexlimdva 3172	. 2 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (∃𝑥 ∈ ω (𝐴 +o 𝑥) = 𝐵 → 𝐴 ⊆ 𝐵))
91	85, 90	impbid 215	1 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ⊆ 𝐵 ↔ ∃𝑥 ∈ ω (𝐴 +o 𝑥) = 𝐵))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 400   ∨ wo 860   = wceq 1567   ∈ wcel 2149   ≠ wne 2964  ∃wrex 3095  {crab 3423   ⊆ wss 3913  ∅c0 4294  ∩ cint 4916  Ord word 6362  Oncon0 6363  suc csuc 6365  (class class class)co 7413  ωcom 7864   +_o coa 8452

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-10 2182  ax-11 2198  ax-12 2219  ax-ext 2741  ax-sep 5261  ax-nul 5273  ax-pr 5407  ax-un 7735

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-nf 1811  df-sb 2098  df-mo 2573  df-eu 2603  df-clab 2748  df-cleq 2761  df-clel 2844  df-nfc 2918  df-ne 2965  df-ral 3086  df-rex 3096  df-reu 3377  df-rab 3424  df-v 3465  df-sbc 3754  df-csb 3862  df-dif 3916  df-un 3918  df-in 3920  df-ss 3930  df-pss 3933  df-nul 4295  df-if 4493  df-pw 4569  df-sn 4595  df-pr 4597  df-op 4601  df-uni 4877  df-int 4917  df-iun 4962  df-br 5114  df-opab 5178  df-mpt 5197  df-tr 5223  df-id 5559  df-eprel 5564  df-po 5572  df-so 5573  df-fr 5617  df-we 5619  df-xp 5670  df-rel 5671  df-cnv 5672  df-co 5673  df-dm 5674  df-rn 5675  df-res 5676  df-ima 5677  df-pred 6305  df-ord 6366  df-on 6367  df-lim 6368  df-suc 6369  df-iota 6495  df-fun 6541  df-fn 6542  df-f 6543  df-f1 6544  df-fo 6545  df-f1o 6546  df-fv 6547  df-ov 7416  df-oprab 7417  df-mpo 7418  df-om 7865  df-2nd 7989  df-frecs 8280  df-wrecs 8311  df-recs 8360  df-rdg 8399  df-oadd 8459

This theorem is referenced by:  nnaordex  8626  eldifsucnn  8652  unfilem1  9267  ttrcltr  9687  hashdom  14417  precsexlem6  28373  precsexlem7  28374