Theorem unxpwdom2 9619

Description: Lemma for unxpwdom 9620. (Contributed by Mario Carneiro, 15-May-2015.)

Assertion

Ref	Expression
unxpwdom2	⊢ ((𝐴 × 𝐴) ≈ (𝐵 ∪ 𝐶) → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶))

Proof of Theorem unxpwdom2

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

Step	Hyp	Ref	Expression
1		ensym 9068	. 2 ⊢ ((𝐴 × 𝐴) ≈ (𝐵 ∪ 𝐶) → (𝐵 ∪ 𝐶) ≈ (𝐴 × 𝐴))
2		bren 9021	. . 3 ⊢ ((𝐵 ∪ 𝐶) ≈ (𝐴 × 𝐴) ↔ ∃𝑓 𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴))
3		ssdif0 4317	. . . . . 6 ⊢ (𝐴 ⊆ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ↔ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) = ∅)
4		dmxpid 5924	. . . . . . . . . . . . . 14 ⊢ dom (𝐴 × 𝐴) = 𝐴
5		f1ofo 6862	. . . . . . . . . . . . . . . . 17 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → 𝑓:(𝐵 ∪ 𝐶)⟶onto(𝐴 × 𝐴))
6		forn 6829	. . . . . . . . . . . . . . . . 17 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶onto(𝐴 × 𝐴) → ran 𝑓 = (𝐴 × 𝐴))
7	5, 6	syl 18	. . . . . . . . . . . . . . . 16 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → ran 𝑓 = (𝐴 × 𝐴))
8		vex 3458	. . . . . . . . . . . . . . . . 17 ⊢ 𝑓 ∈ V
9	8	rnex 7956	. . . . . . . . . . . . . . . 16 ⊢ ran 𝑓 ∈ V
10	7, 9	eqeltrrdi 2873	. . . . . . . . . . . . . . 15 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → (𝐴 × 𝐴) ∈ V)
11	10	dmexd 7949	. . . . . . . . . . . . . 14 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → dom (𝐴 × 𝐴) ∈ V)
12	4, 11	eqeltrrid 2869	. . . . . . . . . . . . 13 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → 𝐴 ∈ V)
13		imassrn 6216	. . . . . . . . . . . . . 14 ⊢ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ⊆ ran ((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓)
14		f1stres 8059	. . . . . . . . . . . . . . . 16 ⊢ (1st ↾ (𝐴 × 𝐴)):(𝐴 × 𝐴)⟶𝐴
15		f1of 6854	. . . . . . . . . . . . . . . 16 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → 𝑓:(𝐵 ∪ 𝐶)⟶(𝐴 × 𝐴))
16		fco 6764	. . . . . . . . . . . . . . . 16 ⊢ (((1st ↾ (𝐴 × 𝐴)):(𝐴 × 𝐴)⟶𝐴 ∧ 𝑓:(𝐵 ∪ 𝐶)⟶(𝐴 × 𝐴)) → ((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓):(𝐵 ∪ 𝐶)⟶𝐴)
17	14, 15, 16	sylancr 599	. . . . . . . . . . . . . . 15 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → ((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓):(𝐵 ∪ 𝐶)⟶𝐴)
18	17	frnd 6748	. . . . . . . . . . . . . 14 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → ran ((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) ⊆ 𝐴)
19	13, 18	sstrid 3924	. . . . . . . . . . . . 13 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ⊆ 𝐴)
20	12, 19	ssexd 5293	. . . . . . . . . . . 12 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ∈ V)
21	20	adantr 486	. . . . . . . . . . 11 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝐴 ⊆ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) → (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ∈ V)
22		simpr 490	. . . . . . . . . . 11 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝐴 ⊆ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) → 𝐴 ⊆ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))
23		ssdomg 9065	. . . . . . . . . . 11 ⊢ ((((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ∈ V → (𝐴 ⊆ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) → 𝐴 ≼ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)))
24	21, 22, 23	sylc 66	. . . . . . . . . 10 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝐴 ⊆ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) → 𝐴 ≼ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))
25		domwdom 9605	. . . . . . . . . 10 ⊢ (𝐴 ≼ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) → 𝐴 ≼* (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))
26	24, 25	syl 18	. . . . . . . . 9 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝐴 ⊆ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) → 𝐴 ≼* (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))
27	17	ffund 6744	. . . . . . . . . . 11 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → Fun ((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓))
28		ssun1 4179	. . . . . . . . . . . 12 ⊢ 𝐵 ⊆ (𝐵 ∪ 𝐶)
29		f1odm 6858	. . . . . . . . . . . . 13 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → dom 𝑓 = (𝐵 ∪ 𝐶))
30	8	dmex 7955	. . . . . . . . . . . . 13 ⊢ dom 𝑓 ∈ V
31	29, 30	eqeltrrdi 2873	. . . . . . . . . . . 12 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → (𝐵 ∪ 𝐶) ∈ V)
32		ssexg 5288	. . . . . . . . . . . 12 ⊢ ((𝐵 ⊆ (𝐵 ∪ 𝐶) ∧ (𝐵 ∪ 𝐶) ∈ V) → 𝐵 ∈ V)
33	28, 31, 32	sylancr 599	. . . . . . . . . . 11 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → 𝐵 ∈ V)
34		wdomima2g 9617	. . . . . . . . . . 11 ⊢ ((Fun ((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) ∧ 𝐵 ∈ V ∧ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ∈ V) → (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ≼* 𝐵)
35	27, 33, 20, 34	syl3anc 1399	. . . . . . . . . 10 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ≼* 𝐵)
36	35	adantr 486	. . . . . . . . 9 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝐴 ⊆ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) → (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ≼* 𝐵)
37		wdomtr 9606	. . . . . . . . 9 ⊢ ((𝐴 ≼* (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ∧ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) ≼* 𝐵) → 𝐴 ≼* 𝐵)
38	26, 36, 37	syl2anc 596	. . . . . . . 8 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝐴 ⊆ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) → 𝐴 ≼* 𝐵)
39	38	orcd 887	. . . . . . 7 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝐴 ⊆ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶))
40	39	ex 418	. . . . . 6 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → (𝐴 ⊆ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵) → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶)))
41	3, 40	biimtrrid 246	. . . . 5 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → ((𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) = ∅ → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶)))
42		n0 4303	. . . . . 6 ⊢ ((𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) ≠ ∅ ↔ ∃𝑥 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)))
43		ssun2 4180	. . . . . . . . . . . . 13 ⊢ 𝐶 ⊆ (𝐵 ∪ 𝐶)
44		ssexg 5288	. . . . . . . . . . . . 13 ⊢ ((𝐶 ⊆ (𝐵 ∪ 𝐶) ∧ (𝐵 ∪ 𝐶) ∈ V) → 𝐶 ∈ V)
45	43, 31, 44	sylancr 599	. . . . . . . . . . . 12 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → 𝐶 ∈ V)
46	45	adantr 486	. . . . . . . . . . 11 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → 𝐶 ∈ V)
47		f1ofn 6855	. . . . . . . . . . . . . . 15 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → 𝑓 Fn (𝐵 ∪ 𝐶))
48		elpreima 7088	. . . . . . . . . . . . . . 15 ⊢ (𝑓 Fn (𝐵 ∪ 𝐶) → (𝑦 ∈ (◡𝑓 “ ({𝑥} × 𝐴)) ↔ (𝑦 ∈ (𝐵 ∪ 𝐶) ∧ (𝑓‘𝑦) ∈ ({𝑥} × 𝐴))))
49	47, 48	syl 18	. . . . . . . . . . . . . 14 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → (𝑦 ∈ (◡𝑓 “ ({𝑥} × 𝐴)) ↔ (𝑦 ∈ (𝐵 ∪ 𝐶) ∧ (𝑓‘𝑦) ∈ ({𝑥} × 𝐴))))
50	49	adantr 486	. . . . . . . . . . . . 13 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → (𝑦 ∈ (◡𝑓 “ ({𝑥} × 𝐴)) ↔ (𝑦 ∈ (𝐵 ∪ 𝐶) ∧ (𝑓‘𝑦) ∈ ({𝑥} × 𝐴))))
51		elun 4155	. . . . . . . . . . . . . . . 16 ⊢ (𝑦 ∈ (𝐵 ∪ 𝐶) ↔ (𝑦 ∈ 𝐵 ∨ 𝑦 ∈ 𝐶))
52		df-or 862	. . . . . . . . . . . . . . . 16 ⊢ ((𝑦 ∈ 𝐵 ∨ 𝑦 ∈ 𝐶) ↔ (¬ 𝑦 ∈ 𝐵 → 𝑦 ∈ 𝐶))
53	51, 52	bitri 278	. . . . . . . . . . . . . . 15 ⊢ (𝑦 ∈ (𝐵 ∪ 𝐶) ↔ (¬ 𝑦 ∈ 𝐵 → 𝑦 ∈ 𝐶))
54		eldifn 4071	. . . . . . . . . . . . . . . . . . 19 ⊢ (𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) → ¬ 𝑥 ∈ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))
55	54	ad2antlr 740	. . . . . . . . . . . . . . . . . 18 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ (𝑓‘𝑦) ∈ ({𝑥} × 𝐴)) → ¬ 𝑥 ∈ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))
56	15	ad2antrr 739	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → 𝑓:(𝐵 ∪ 𝐶)⟶(𝐴 × 𝐴))
57		simprr 785	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → 𝑦 ∈ 𝐵)
58	28, 57	sselid 3911	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → 𝑦 ∈ (𝐵 ∪ 𝐶))
59		fvco3 7016	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶(𝐴 × 𝐴) ∧ 𝑦 ∈ (𝐵 ∪ 𝐶)) → (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓)‘𝑦) = ((1st ↾ (𝐴 × 𝐴))‘(𝑓‘𝑦)))
60	56, 58, 59	syl2anc 596	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓)‘𝑦) = ((1st ↾ (𝐴 × 𝐴))‘(𝑓‘𝑦)))
61		eldifi 4070	. . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 ⊢ (𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) → 𝑥 ∈ 𝐴)
62	61	adantl 487	. . . . . . . . . . . . . . . . . . . . . . . . . . . 28 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → 𝑥 ∈ 𝐴)
63	62	snssd 4749	. . . . . . . . . . . . . . . . . . . . . . . . . . 27 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → {𝑥} ⊆ 𝐴)
64		xpss1 5677	. . . . . . . . . . . . . . . . . . . . . . . . . . 27 ⊢ ({𝑥} ⊆ 𝐴 → ({𝑥} × 𝐴) ⊆ (𝐴 × 𝐴))
65	63, 64	syl 18	. . . . . . . . . . . . . . . . . . . . . . . . . 26 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → ({𝑥} × 𝐴) ⊆ (𝐴 × 𝐴))
66	65	adantr 486	. . . . . . . . . . . . . . . . . . . . . . . . 25 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → ({𝑥} × 𝐴) ⊆ (𝐴 × 𝐴))
67		simprl 783	. . . . . . . . . . . . . . . . . . . . . . . . 25 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → (𝑓‘𝑦) ∈ ({𝑥} × 𝐴))
68	66, 67	sseldd 3914	. . . . . . . . . . . . . . . . . . . . . . . 24 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → (𝑓‘𝑦) ∈ (𝐴 × 𝐴))
69	68	fvresd 6936	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → ((1st ↾ (𝐴 × 𝐴))‘(𝑓‘𝑦)) = (1st ‘(𝑓‘𝑦)))
70		xp1st 8067	. . . . . . . . . . . . . . . . . . . . . . . 24 ⊢ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) → (1st ‘(𝑓‘𝑦)) ∈ {𝑥})
71	67, 70	syl 18	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → (1st ‘(𝑓‘𝑦)) ∈ {𝑥})
72	69, 71	eqeltrd 2864	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → ((1st ↾ (𝐴 × 𝐴))‘(𝑓‘𝑦)) ∈ {𝑥})
73		elsni 4601	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (((1st ↾ (𝐴 × 𝐴))‘(𝑓‘𝑦)) ∈ {𝑥} → ((1st ↾ (𝐴 × 𝐴))‘(𝑓‘𝑦)) = 𝑥)
74	72, 73	syl 18	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → ((1st ↾ (𝐴 × 𝐴))‘(𝑓‘𝑦)) = 𝑥)
75	60, 74	eqtrd 2798	. . . . . . . . . . . . . . . . . . . 20 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓)‘𝑦) = 𝑥)
76	17	ffnd 6740	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → ((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) Fn (𝐵 ∪ 𝐶))
77	76	ad2antrr 739	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → ((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) Fn (𝐵 ∪ 𝐶))
78	28	a1i 11	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → 𝐵 ⊆ (𝐵 ∪ 𝐶))
79		fnfvima 7270	. . . . . . . . . . . . . . . . . . . . 21 ⊢ ((((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) Fn (𝐵 ∪ 𝐶) ∧ 𝐵 ⊆ (𝐵 ∪ 𝐶) ∧ 𝑦 ∈ 𝐵) → (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓)‘𝑦) ∈ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))
80	77, 78, 57, 79	syl3anc 1399	. . . . . . . . . . . . . . . . . . . 20 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓)‘𝑦) ∈ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))
81	75, 80	eqeltrrd 2865	. . . . . . . . . . . . . . . . . . 19 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) ∧ 𝑦 ∈ 𝐵)) → 𝑥 ∈ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))
82	81	expr 462	. . . . . . . . . . . . . . . . . 18 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ (𝑓‘𝑦) ∈ ({𝑥} × 𝐴)) → (𝑦 ∈ 𝐵 → 𝑥 ∈ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)))
83	55, 82	mtod 201	. . . . . . . . . . . . . . . . 17 ⊢ (((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) ∧ (𝑓‘𝑦) ∈ ({𝑥} × 𝐴)) → ¬ 𝑦 ∈ 𝐵)
84	83	ex 418	. . . . . . . . . . . . . . . 16 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) → ¬ 𝑦 ∈ 𝐵))
85	84	imim1d 83	. . . . . . . . . . . . . . 15 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → ((¬ 𝑦 ∈ 𝐵 → 𝑦 ∈ 𝐶) → ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) → 𝑦 ∈ 𝐶)))
86	53, 85	biimtrid 245	. . . . . . . . . . . . . 14 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → (𝑦 ∈ (𝐵 ∪ 𝐶) → ((𝑓‘𝑦) ∈ ({𝑥} × 𝐴) → 𝑦 ∈ 𝐶)))
87	86	impd 416	. . . . . . . . . . . . 13 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → ((𝑦 ∈ (𝐵 ∪ 𝐶) ∧ (𝑓‘𝑦) ∈ ({𝑥} × 𝐴)) → 𝑦 ∈ 𝐶))
88	50, 87	sylbid 243	. . . . . . . . . . . 12 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → (𝑦 ∈ (◡𝑓 “ ({𝑥} × 𝐴)) → 𝑦 ∈ 𝐶))
89	88	ssrdv 3919	. . . . . . . . . . 11 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → (◡𝑓 “ ({𝑥} × 𝐴)) ⊆ 𝐶)
90		ssdomg 9065	. . . . . . . . . . 11 ⊢ (𝐶 ∈ V → ((◡𝑓 “ ({𝑥} × 𝐴)) ⊆ 𝐶 → (◡𝑓 “ ({𝑥} × 𝐴)) ≼ 𝐶))
91	46, 89, 90	sylc 66	. . . . . . . . . 10 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → (◡𝑓 “ ({𝑥} × 𝐴)) ≼ 𝐶)
92		f1ocnv 6867	. . . . . . . . . . . . . . 15 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → ◡𝑓:(𝐴 × 𝐴)⟶1-1onto(𝐵 ∪ 𝐶))
93		f1of1 6853	. . . . . . . . . . . . . . 15 ⊢ (◡𝑓:(𝐴 × 𝐴)⟶1-1onto(𝐵 ∪ 𝐶) → ◡𝑓:(𝐴 × 𝐴)⟶1-1(𝐵 ∪ 𝐶))
94	92, 93	syl 18	. . . . . . . . . . . . . 14 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → ◡𝑓:(𝐴 × 𝐴)⟶1-1(𝐵 ∪ 𝐶))
95	94	adantr 486	. . . . . . . . . . . . 13 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → ◡𝑓:(𝐴 × 𝐴)⟶1-1(𝐵 ∪ 𝐶))
96	31	adantr 486	. . . . . . . . . . . . 13 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → (𝐵 ∪ 𝐶) ∈ V)
97		vsnex 5400	. . . . . . . . . . . . . 14 ⊢ {𝑥} ∈ V
98	12	adantr 486	. . . . . . . . . . . . . 14 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → 𝐴 ∈ V)
99		xpexg 7796	. . . . . . . . . . . . . 14 ⊢ (({𝑥} ∈ V ∧ 𝐴 ∈ V) → ({𝑥} × 𝐴) ∈ V)
100	97, 98, 99	sylancr 599	. . . . . . . . . . . . 13 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → ({𝑥} × 𝐴) ∈ V)
101		f1imaen2g 9080	. . . . . . . . . . . . 13 ⊢ (((◡𝑓:(𝐴 × 𝐴)⟶1-1(𝐵 ∪ 𝐶) ∧ (𝐵 ∪ 𝐶) ∈ V) ∧ (({𝑥} × 𝐴) ⊆ (𝐴 × 𝐴) ∧ ({𝑥} × 𝐴) ∈ V)) → (◡𝑓 “ ({𝑥} × 𝐴)) ≈ ({𝑥} × 𝐴))
102	95, 96, 65, 100, 101	syl22anc 852	. . . . . . . . . . . 12 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → (◡𝑓 “ ({𝑥} × 𝐴)) ≈ ({𝑥} × 𝐴))
103		vex 3458	. . . . . . . . . . . . 13 ⊢ 𝑥 ∈ V
104		xpsnen2g 9127	. . . . . . . . . . . . 13 ⊢ ((𝑥 ∈ V ∧ 𝐴 ∈ V) → ({𝑥} × 𝐴) ≈ 𝐴)
105	103, 98, 104	sylancr 599	. . . . . . . . . . . 12 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → ({𝑥} × 𝐴) ≈ 𝐴)
106		entr 9071	. . . . . . . . . . . 12 ⊢ (((◡𝑓 “ ({𝑥} × 𝐴)) ≈ ({𝑥} × 𝐴) ∧ ({𝑥} × 𝐴) ≈ 𝐴) → (◡𝑓 “ ({𝑥} × 𝐴)) ≈ 𝐴)
107	102, 105, 106	syl2anc 596	. . . . . . . . . . 11 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → (◡𝑓 “ ({𝑥} × 𝐴)) ≈ 𝐴)
108		domen1 9176	. . . . . . . . . . 11 ⊢ ((◡𝑓 “ ({𝑥} × 𝐴)) ≈ 𝐴 → ((◡𝑓 “ ({𝑥} × 𝐴)) ≼ 𝐶 ↔ 𝐴 ≼ 𝐶))
109	107, 108	syl 18	. . . . . . . . . 10 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → ((◡𝑓 “ ({𝑥} × 𝐴)) ≼ 𝐶 ↔ 𝐴 ≼ 𝐶))
110	91, 109	mpbid 235	. . . . . . . . 9 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → 𝐴 ≼ 𝐶)
111	110	olcd 888	. . . . . . . 8 ⊢ ((𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) ∧ 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵))) → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶))
112	111	ex 418	. . . . . . 7 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → (𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶)))
113	112	exlimdv 1968	. . . . . 6 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → (∃𝑥 𝑥 ∈ (𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶)))
114	42, 113	biimtrid 245	. . . . 5 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → ((𝐴 ∖ (((1st ↾ (𝐴 × 𝐴)) ∘ 𝑓) “ 𝐵)) ≠ ∅ → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶)))
115	41, 114	pm2.61dne 3045	. . . 4 ⊢ (𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶))
116	115	exlimiv 1965	. . 3 ⊢ (∃𝑓 𝑓:(𝐵 ∪ 𝐶)⟶1-1onto(𝐴 × 𝐴) → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶))
117	2, 116	sylbi 220	. 2 ⊢ ((𝐵 ∪ 𝐶) ≈ (𝐴 × 𝐴) → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶))
118	1, 117	syl 18	1 ⊢ ((𝐴 × 𝐴) ≈ (𝐵 ∪ 𝐶) → (𝐴 ≼* 𝐵 ∨ 𝐴 ≼ 𝐶))

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 401   ∨ wo 861   = wceq 1570  ∃wex 1812   ∈ wcel 2147   ≠ wne 2959  Vcvv 3454   ⊆ wss 3900   ∖ cdif 4048   ∪ cun 4152  ∅c0 4281  {csn 4588   class class class wbr 5108   × cxp 5656  ^◡ccnv 5657  dom cdm 5658  ran crn 5659   ↾ cres 5660   “ cima 5661   ∘ ccom 5662  Fun wfun 6560   Fn wfn 6561  ⟶wf 6562  ⟶1-1wf1 6563  ⟶ontowfo 6564  ⟶1-1ontowf1o 6565  ‘cfv 6566  1^st c1st 8033   ≈ cen 9008   ≼ cdom 9009   ≼^* cwdom 9595

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1945  ax-6 2002  ax-7 2043  ax-8 2149  ax-9 2157  ax-10 2180  ax-11 2197  ax-12 2216  ax-ext 2735  ax-sep 5255  ax-nul 5266  ax-pow 5334  ax-pr 5398  ax-un 7783

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2102  df-mo 2567  df-eu 2597  df-clab 2742  df-cleq 2755  df-clel 2839  df-nfc 2913  df-ne 2960  df-ral 3081  df-rex 3091  df-rab 3417  df-v 3456  df-sbc 3743  df-csb 3852  df-ss 3901  df-dif 4050  df-in 4094  df-un 4154  df-nul 4282  df-if 4486  df-pw 4562  df-sn 4589  df-pr 4591  df-op 4841  df-uni 4873  df-int 4913  df-iun 4958  df-br 5109  df-opab 5174  df-mpt 5193  df-id 5553  df-xp 5664  df-rel 5665  df-cnv 5666  df-co 5667  df-dm 5668  df-rn 5669  df-res 5670  df-ima 5671  df-iota 6520  df-fun 6568  df-fn 6569  df-f 6570  df-f1 6571  df-fo 6572  df-f1o 6573  df-fv 6574  df-1st 8035  df-2nd 8036  df-er 8755  df-en 9012  df-dom 9013  df-sdom 9014  df-wdom 9596

This theorem is used by:  unxpwdom  9620  ttac  44309