Proof of Theorem mapsnd
Step | Hyp | Ref
| Expression |
1 | | mapsnd.1 |
. . . 4
⊢ (𝜑 → 𝐴 ∈ 𝑉) |
2 | | snex 5349 |
. . . . 5
⊢ {𝐵} ∈ V |
3 | 2 | a1i 11 |
. . . 4
⊢ (𝜑 → {𝐵} ∈ V) |
4 | 1, 3 | elmapd 8587 |
. . 3
⊢ (𝜑 → (𝑓 ∈ (𝐴 ↑m {𝐵}) ↔ 𝑓:{𝐵}⟶𝐴)) |
5 | | ffn 6584 |
. . . . . . . . 9
⊢ (𝑓:{𝐵}⟶𝐴 → 𝑓 Fn {𝐵}) |
6 | | mapsnd.2 |
. . . . . . . . . 10
⊢ (𝜑 → 𝐵 ∈ 𝑊) |
7 | | snidg 4592 |
. . . . . . . . . 10
⊢ (𝐵 ∈ 𝑊 → 𝐵 ∈ {𝐵}) |
8 | 6, 7 | syl 17 |
. . . . . . . . 9
⊢ (𝜑 → 𝐵 ∈ {𝐵}) |
9 | | fneu 6527 |
. . . . . . . . 9
⊢ ((𝑓 Fn {𝐵} ∧ 𝐵 ∈ {𝐵}) → ∃!𝑦 𝐵𝑓𝑦) |
10 | 5, 8, 9 | syl2anr 596 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → ∃!𝑦 𝐵𝑓𝑦) |
11 | | euabsn 4659 |
. . . . . . . . . 10
⊢
(∃!𝑦 𝐵𝑓𝑦 ↔ ∃𝑦{𝑦 ∣ 𝐵𝑓𝑦} = {𝑦}) |
12 | | frel 6589 |
. . . . . . . . . . . . . 14
⊢ (𝑓:{𝐵}⟶𝐴 → Rel 𝑓) |
13 | | relimasn 5981 |
. . . . . . . . . . . . . 14
⊢ (Rel
𝑓 → (𝑓 “ {𝐵}) = {𝑦 ∣ 𝐵𝑓𝑦}) |
14 | 12, 13 | syl 17 |
. . . . . . . . . . . . 13
⊢ (𝑓:{𝐵}⟶𝐴 → (𝑓 “ {𝐵}) = {𝑦 ∣ 𝐵𝑓𝑦}) |
15 | | fdm 6593 |
. . . . . . . . . . . . . . 15
⊢ (𝑓:{𝐵}⟶𝐴 → dom 𝑓 = {𝐵}) |
16 | 15 | imaeq2d 5958 |
. . . . . . . . . . . . . 14
⊢ (𝑓:{𝐵}⟶𝐴 → (𝑓 “ dom 𝑓) = (𝑓 “ {𝐵})) |
17 | | imadmrn 5968 |
. . . . . . . . . . . . . 14
⊢ (𝑓 “ dom 𝑓) = ran 𝑓 |
18 | 16, 17 | eqtr3di 2794 |
. . . . . . . . . . . . 13
⊢ (𝑓:{𝐵}⟶𝐴 → (𝑓 “ {𝐵}) = ran 𝑓) |
19 | 14, 18 | eqtr3d 2780 |
. . . . . . . . . . . 12
⊢ (𝑓:{𝐵}⟶𝐴 → {𝑦 ∣ 𝐵𝑓𝑦} = ran 𝑓) |
20 | 19 | eqeq1d 2740 |
. . . . . . . . . . 11
⊢ (𝑓:{𝐵}⟶𝐴 → ({𝑦 ∣ 𝐵𝑓𝑦} = {𝑦} ↔ ran 𝑓 = {𝑦})) |
21 | 20 | exbidv 1925 |
. . . . . . . . . 10
⊢ (𝑓:{𝐵}⟶𝐴 → (∃𝑦{𝑦 ∣ 𝐵𝑓𝑦} = {𝑦} ↔ ∃𝑦ran 𝑓 = {𝑦})) |
22 | 11, 21 | syl5bb 282 |
. . . . . . . . 9
⊢ (𝑓:{𝐵}⟶𝐴 → (∃!𝑦 𝐵𝑓𝑦 ↔ ∃𝑦ran 𝑓 = {𝑦})) |
23 | 22 | adantl 481 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → (∃!𝑦 𝐵𝑓𝑦 ↔ ∃𝑦ran 𝑓 = {𝑦})) |
24 | 10, 23 | mpbid 231 |
. . . . . . 7
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → ∃𝑦ran 𝑓 = {𝑦}) |
25 | | frn 6591 |
. . . . . . . . . . . . 13
⊢ (𝑓:{𝐵}⟶𝐴 → ran 𝑓 ⊆ 𝐴) |
26 | 25 | sseld 3916 |
. . . . . . . . . . . 12
⊢ (𝑓:{𝐵}⟶𝐴 → (𝑦 ∈ ran 𝑓 → 𝑦 ∈ 𝐴)) |
27 | | vsnid 4595 |
. . . . . . . . . . . . 13
⊢ 𝑦 ∈ {𝑦} |
28 | | eleq2 2827 |
. . . . . . . . . . . . 13
⊢ (ran
𝑓 = {𝑦} → (𝑦 ∈ ran 𝑓 ↔ 𝑦 ∈ {𝑦})) |
29 | 27, 28 | mpbiri 257 |
. . . . . . . . . . . 12
⊢ (ran
𝑓 = {𝑦} → 𝑦 ∈ ran 𝑓) |
30 | 26, 29 | impel 505 |
. . . . . . . . . . 11
⊢ ((𝑓:{𝐵}⟶𝐴 ∧ ran 𝑓 = {𝑦}) → 𝑦 ∈ 𝐴) |
31 | 30 | adantll 710 |
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → 𝑦 ∈ 𝐴) |
32 | | ffrn 6598 |
. . . . . . . . . . . . . 14
⊢ (𝑓:{𝐵}⟶𝐴 → 𝑓:{𝐵}⟶ran 𝑓) |
33 | | feq3 6567 |
. . . . . . . . . . . . . 14
⊢ (ran
𝑓 = {𝑦} → (𝑓:{𝐵}⟶ran 𝑓 ↔ 𝑓:{𝐵}⟶{𝑦})) |
34 | 32, 33 | syl5ibcom 244 |
. . . . . . . . . . . . 13
⊢ (𝑓:{𝐵}⟶𝐴 → (ran 𝑓 = {𝑦} → 𝑓:{𝐵}⟶{𝑦})) |
35 | 34 | imp 406 |
. . . . . . . . . . . 12
⊢ ((𝑓:{𝐵}⟶𝐴 ∧ ran 𝑓 = {𝑦}) → 𝑓:{𝐵}⟶{𝑦}) |
36 | 35 | adantll 710 |
. . . . . . . . . . 11
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → 𝑓:{𝐵}⟶{𝑦}) |
37 | 6 | ad2antrr 722 |
. . . . . . . . . . . 12
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → 𝐵 ∈ 𝑊) |
38 | | vex 3426 |
. . . . . . . . . . . 12
⊢ 𝑦 ∈ V |
39 | | fsng 6991 |
. . . . . . . . . . . 12
⊢ ((𝐵 ∈ 𝑊 ∧ 𝑦 ∈ V) → (𝑓:{𝐵}⟶{𝑦} ↔ 𝑓 = {〈𝐵, 𝑦〉})) |
40 | 37, 38, 39 | sylancl 585 |
. . . . . . . . . . 11
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → (𝑓:{𝐵}⟶{𝑦} ↔ 𝑓 = {〈𝐵, 𝑦〉})) |
41 | 36, 40 | mpbid 231 |
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → 𝑓 = {〈𝐵, 𝑦〉}) |
42 | 31, 41 | jca 511 |
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → (𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉})) |
43 | 42 | ex 412 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → (ran 𝑓 = {𝑦} → (𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉}))) |
44 | 43 | eximdv 1921 |
. . . . . . 7
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → (∃𝑦ran 𝑓 = {𝑦} → ∃𝑦(𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉}))) |
45 | 24, 44 | mpd 15 |
. . . . . 6
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → ∃𝑦(𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉})) |
46 | | df-rex 3069 |
. . . . . 6
⊢
(∃𝑦 ∈
𝐴 𝑓 = {〈𝐵, 𝑦〉} ↔ ∃𝑦(𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉})) |
47 | 45, 46 | sylibr 233 |
. . . . 5
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → ∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉}) |
48 | 47 | ex 412 |
. . . 4
⊢ (𝜑 → (𝑓:{𝐵}⟶𝐴 → ∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉})) |
49 | | f1osng 6740 |
. . . . . . . . . . 11
⊢ ((𝐵 ∈ 𝑊 ∧ 𝑦 ∈ V) → {〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦}) |
50 | 6, 38, 49 | sylancl 585 |
. . . . . . . . . 10
⊢ (𝜑 → {〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦}) |
51 | 50 | adantr 480 |
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → {〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦}) |
52 | | f1oeq1 6688 |
. . . . . . . . . . 11
⊢ (𝑓 = {〈𝐵, 𝑦〉} → (𝑓:{𝐵}–1-1-onto→{𝑦} ↔ {〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦})) |
53 | 52 | bicomd 222 |
. . . . . . . . . 10
⊢ (𝑓 = {〈𝐵, 𝑦〉} → ({〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦} ↔ 𝑓:{𝐵}–1-1-onto→{𝑦})) |
54 | 53 | adantl 481 |
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → ({〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦} ↔ 𝑓:{𝐵}–1-1-onto→{𝑦})) |
55 | 51, 54 | mpbid 231 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → 𝑓:{𝐵}–1-1-onto→{𝑦}) |
56 | | f1of 6700 |
. . . . . . . 8
⊢ (𝑓:{𝐵}–1-1-onto→{𝑦} → 𝑓:{𝐵}⟶{𝑦}) |
57 | 55, 56 | syl 17 |
. . . . . . 7
⊢ ((𝜑 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → 𝑓:{𝐵}⟶{𝑦}) |
58 | 57 | 3adant2 1129 |
. . . . . 6
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → 𝑓:{𝐵}⟶{𝑦}) |
59 | | snssi 4738 |
. . . . . . 7
⊢ (𝑦 ∈ 𝐴 → {𝑦} ⊆ 𝐴) |
60 | 59 | 3ad2ant2 1132 |
. . . . . 6
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → {𝑦} ⊆ 𝐴) |
61 | 58, 60 | fssd 6602 |
. . . . 5
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → 𝑓:{𝐵}⟶𝐴) |
62 | 61 | rexlimdv3a 3214 |
. . . 4
⊢ (𝜑 → (∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉} → 𝑓:{𝐵}⟶𝐴)) |
63 | 48, 62 | impbid 211 |
. . 3
⊢ (𝜑 → (𝑓:{𝐵}⟶𝐴 ↔ ∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉})) |
64 | 4, 63 | bitrd 278 |
. 2
⊢ (𝜑 → (𝑓 ∈ (𝐴 ↑m {𝐵}) ↔ ∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉})) |
65 | 64 | abbi2dv 2876 |
1
⊢ (𝜑 → (𝐴 ↑m {𝐵}) = {𝑓 ∣ ∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉}}) |