Metamath Proof Explorer


Theorem domss2

Description: A corollary of disjenex . If F is an injection from A to B then G is a right inverse of F from B to a superset of A . (Contributed by Mario Carneiro, 7-Feb-2015) (Revised by Mario Carneiro, 24-Jun-2015)

Ref Expression
Hypothesis domss2.1 𝐺 = ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
Assertion domss2 ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐺 : 𝐵1-1-onto→ ran 𝐺𝐴 ⊆ ran 𝐺 ∧ ( 𝐺𝐹 ) = ( I ↾ 𝐴 ) ) )

Proof

Step Hyp Ref Expression
1 domss2.1 𝐺 = ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
2 f1f1orn ( 𝐹 : 𝐴1-1𝐵𝐹 : 𝐴1-1-onto→ ran 𝐹 )
3 2 3ad2ant1 ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → 𝐹 : 𝐴1-1-onto→ ran 𝐹 )
4 simp2 ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → 𝐴𝑉 )
5 rnexg ( 𝐴𝑉 → ran 𝐴 ∈ V )
6 4 5 syl ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ran 𝐴 ∈ V )
7 uniexg ( ran 𝐴 ∈ V → ran 𝐴 ∈ V )
8 pwexg ( ran 𝐴 ∈ V → 𝒫 ran 𝐴 ∈ V )
9 6 7 8 3syl ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → 𝒫 ran 𝐴 ∈ V )
10 1stconst ( 𝒫 ran 𝐴 ∈ V → ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) : ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) –1-1-onto→ ( 𝐵 ∖ ran 𝐹 ) )
11 9 10 syl ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) : ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) –1-1-onto→ ( 𝐵 ∖ ran 𝐹 ) )
12 difexg ( 𝐵𝑊 → ( 𝐵 ∖ ran 𝐹 ) ∈ V )
13 12 3ad2ant3 ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐵 ∖ ran 𝐹 ) ∈ V )
14 disjen ( ( 𝐴𝑉 ∧ ( 𝐵 ∖ ran 𝐹 ) ∈ V ) → ( ( 𝐴 ∩ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) = ∅ ∧ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ≈ ( 𝐵 ∖ ran 𝐹 ) ) )
15 4 13 14 syl2anc ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( ( 𝐴 ∩ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) = ∅ ∧ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ≈ ( 𝐵 ∖ ran 𝐹 ) ) )
16 15 simpld ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐴 ∩ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) = ∅ )
17 disjdif ( ran 𝐹 ∩ ( 𝐵 ∖ ran 𝐹 ) ) = ∅
18 17 a1i ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( ran 𝐹 ∩ ( 𝐵 ∖ ran 𝐹 ) ) = ∅ )
19 f1oun ( ( ( 𝐹 : 𝐴1-1-onto→ ran 𝐹 ∧ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) : ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) –1-1-onto→ ( 𝐵 ∖ ran 𝐹 ) ) ∧ ( ( 𝐴 ∩ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) = ∅ ∧ ( ran 𝐹 ∩ ( 𝐵 ∖ ran 𝐹 ) ) = ∅ ) ) → ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) : ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) –1-1-onto→ ( ran 𝐹 ∪ ( 𝐵 ∖ ran 𝐹 ) ) )
20 3 11 16 18 19 syl22anc ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) : ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) –1-1-onto→ ( ran 𝐹 ∪ ( 𝐵 ∖ ran 𝐹 ) ) )
21 undif2 ( ran 𝐹 ∪ ( 𝐵 ∖ ran 𝐹 ) ) = ( ran 𝐹𝐵 )
22 f1f ( 𝐹 : 𝐴1-1𝐵𝐹 : 𝐴𝐵 )
23 22 3ad2ant1 ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → 𝐹 : 𝐴𝐵 )
24 23 frnd ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ran 𝐹𝐵 )
25 ssequn1 ( ran 𝐹𝐵 ↔ ( ran 𝐹𝐵 ) = 𝐵 )
26 24 25 sylib ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( ran 𝐹𝐵 ) = 𝐵 )
27 21 26 syl5eq ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( ran 𝐹 ∪ ( 𝐵 ∖ ran 𝐹 ) ) = 𝐵 )
28 27 f1oeq3d ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) : ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) –1-1-onto→ ( ran 𝐹 ∪ ( 𝐵 ∖ ran 𝐹 ) ) ↔ ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) : ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) –1-1-onto𝐵 ) )
29 20 28 mpbid ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) : ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) –1-1-onto𝐵 )
30 f1ocnv ( ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) : ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) –1-1-onto𝐵 ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) : 𝐵1-1-onto→ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
31 29 30 syl ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) : 𝐵1-1-onto→ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
32 f1oeq1 ( 𝐺 = ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) → ( 𝐺 : 𝐵1-1-onto→ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↔ ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) : 𝐵1-1-onto→ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) )
33 1 32 ax-mp ( 𝐺 : 𝐵1-1-onto→ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↔ ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) : 𝐵1-1-onto→ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
34 31 33 sylibr ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → 𝐺 : 𝐵1-1-onto→ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
35 f1ofo ( 𝐺 : 𝐵1-1-onto→ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) → 𝐺 : 𝐵onto→ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
36 forn ( 𝐺 : 𝐵onto→ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) → ran 𝐺 = ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
37 34 35 36 3syl ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ran 𝐺 = ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
38 37 f1oeq3d ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐺 : 𝐵1-1-onto→ ran 𝐺𝐺 : 𝐵1-1-onto→ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) )
39 34 38 mpbird ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → 𝐺 : 𝐵1-1-onto→ ran 𝐺 )
40 ssun1 𝐴 ⊆ ( 𝐴 ∪ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) )
41 40 37 sseqtrrid ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → 𝐴 ⊆ ran 𝐺 )
42 ssid ran 𝐹 ⊆ ran 𝐹
43 cores ( ran 𝐹 ⊆ ran 𝐹 → ( ( 𝐺 ↾ ran 𝐹 ) ∘ 𝐹 ) = ( 𝐺𝐹 ) )
44 42 43 ax-mp ( ( 𝐺 ↾ ran 𝐹 ) ∘ 𝐹 ) = ( 𝐺𝐹 )
45 dmres dom ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) = ( ran 𝐹 ∩ dom ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
46 f1ocnv ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) : ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) –1-1-onto→ ( 𝐵 ∖ ran 𝐹 ) → ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) : ( 𝐵 ∖ ran 𝐹 ) –1-1-onto→ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) )
47 f1odm ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) : ( 𝐵 ∖ ran 𝐹 ) –1-1-onto→ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) → dom ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) = ( 𝐵 ∖ ran 𝐹 ) )
48 11 46 47 3syl ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → dom ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) = ( 𝐵 ∖ ran 𝐹 ) )
49 48 ineq2d ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( ran 𝐹 ∩ dom ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) = ( ran 𝐹 ∩ ( 𝐵 ∖ ran 𝐹 ) ) )
50 49 17 eqtrdi ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( ran 𝐹 ∩ dom ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) = ∅ )
51 45 50 syl5eq ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → dom ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) = ∅ )
52 relres Rel ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 )
53 reldm0 ( Rel ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) → ( ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) = ∅ ↔ dom ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) = ∅ ) )
54 52 53 ax-mp ( ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) = ∅ ↔ dom ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) = ∅ )
55 51 54 sylibr ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) = ∅ )
56 55 uneq2d ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐹 ∪ ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) ) = ( 𝐹 ∪ ∅ ) )
57 cnvun ( 𝐹 ∪ ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) = ( 𝐹 ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
58 1 57 eqtri 𝐺 = ( 𝐹 ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) )
59 58 reseq1i ( 𝐺 ↾ ran 𝐹 ) = ( ( 𝐹 ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) ↾ ran 𝐹 )
60 resundir ( ( 𝐹 ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ) ↾ ran 𝐹 ) = ( ( 𝐹 ↾ ran 𝐹 ) ∪ ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) )
61 df-rn ran 𝐹 = dom 𝐹
62 61 reseq2i ( 𝐹 ↾ ran 𝐹 ) = ( 𝐹 ↾ dom 𝐹 )
63 relcnv Rel 𝐹
64 resdm ( Rel 𝐹 → ( 𝐹 ↾ dom 𝐹 ) = 𝐹 )
65 63 64 ax-mp ( 𝐹 ↾ dom 𝐹 ) = 𝐹
66 62 65 eqtri ( 𝐹 ↾ ran 𝐹 ) = 𝐹
67 66 uneq1i ( ( 𝐹 ↾ ran 𝐹 ) ∪ ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) ) = ( 𝐹 ∪ ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) )
68 59 60 67 3eqtrri ( 𝐹 ∪ ( ( 1st ↾ ( ( 𝐵 ∖ ran 𝐹 ) × { 𝒫 ran 𝐴 } ) ) ↾ ran 𝐹 ) ) = ( 𝐺 ↾ ran 𝐹 )
69 un0 ( 𝐹 ∪ ∅ ) = 𝐹
70 56 68 69 3eqtr3g ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐺 ↾ ran 𝐹 ) = 𝐹 )
71 70 coeq1d ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( ( 𝐺 ↾ ran 𝐹 ) ∘ 𝐹 ) = ( 𝐹𝐹 ) )
72 f1cocnv1 ( 𝐹 : 𝐴1-1𝐵 → ( 𝐹𝐹 ) = ( I ↾ 𝐴 ) )
73 72 3ad2ant1 ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐹𝐹 ) = ( I ↾ 𝐴 ) )
74 71 73 eqtrd ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( ( 𝐺 ↾ ran 𝐹 ) ∘ 𝐹 ) = ( I ↾ 𝐴 ) )
75 44 74 syl5eqr ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐺𝐹 ) = ( I ↾ 𝐴 ) )
76 39 41 75 3jca ( ( 𝐹 : 𝐴1-1𝐵𝐴𝑉𝐵𝑊 ) → ( 𝐺 : 𝐵1-1-onto→ ran 𝐺𝐴 ⊆ ran 𝐺 ∧ ( 𝐺𝐹 ) = ( I ↾ 𝐴 ) ) )