Proof of Theorem mapsnd
| Step | Hyp | Ref
| Expression |
| 1 | | mapsnd.1 |
. . . 4
⊢ (𝜑 → 𝐴 ∈ 𝑉) |
| 2 | | mapsnd.2 |
. . . . 5
⊢ (𝜑 → 𝐵 ∈ 𝑊) |
| 3 | | snexg 4289 |
. . . . 5
⊢ (𝐵 ∈ 𝑊 → {𝐵} ∈ V) |
| 4 | 2, 3 | syl 14 |
. . . 4
⊢ (𝜑 → {𝐵} ∈ V) |
| 5 | 1, 4 | elmapd 6887 |
. . 3
⊢ (𝜑 → (𝑓 ∈ (𝐴 ↑𝑚 {𝐵}) ↔ 𝑓:{𝐵}⟶𝐴)) |
| 6 | | ffn 5499 |
. . . . . . . . 9
⊢ (𝑓:{𝐵}⟶𝐴 → 𝑓 Fn {𝐵}) |
| 7 | | snidg 3711 |
. . . . . . . . . 10
⊢ (𝐵 ∈ 𝑊 → 𝐵 ∈ {𝐵}) |
| 8 | 2, 7 | syl 14 |
. . . . . . . . 9
⊢ (𝜑 → 𝐵 ∈ {𝐵}) |
| 9 | | fneu 5453 |
. . . . . . . . 9
⊢ ((𝑓 Fn {𝐵} ∧ 𝐵 ∈ {𝐵}) → ∃!𝑦 𝐵𝑓𝑦) |
| 10 | 6, 8, 9 | syl2anr 290 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → ∃!𝑦 𝐵𝑓𝑦) |
| 11 | | euabsn 3754 |
. . . . . . . . 9
⊢
(∃!𝑦 𝐵𝑓𝑦 ↔ ∃𝑦{𝑦 ∣ 𝐵𝑓𝑦} = {𝑦}) |
| 12 | | imasng 5118 |
. . . . . . . . . . . . 13
⊢ (𝐵 ∈ 𝑊 → (𝑓 “ {𝐵}) = {𝑦 ∣ 𝐵𝑓𝑦}) |
| 13 | 2, 12 | syl 14 |
. . . . . . . . . . . 12
⊢ (𝜑 → (𝑓 “ {𝐵}) = {𝑦 ∣ 𝐵𝑓𝑦}) |
| 14 | | fdm 5505 |
. . . . . . . . . . . . . 14
⊢ (𝑓:{𝐵}⟶𝐴 → dom 𝑓 = {𝐵}) |
| 15 | 14 | imaeq2d 5092 |
. . . . . . . . . . . . 13
⊢ (𝑓:{𝐵}⟶𝐴 → (𝑓 “ dom 𝑓) = (𝑓 “ {𝐵})) |
| 16 | | imadmrn 5102 |
. . . . . . . . . . . . 13
⊢ (𝑓 “ dom 𝑓) = ran 𝑓 |
| 17 | 15, 16 | eqtr3di 2280 |
. . . . . . . . . . . 12
⊢ (𝑓:{𝐵}⟶𝐴 → (𝑓 “ {𝐵}) = ran 𝑓) |
| 18 | 13, 17 | sylan9req 2286 |
. . . . . . . . . . 11
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → {𝑦 ∣ 𝐵𝑓𝑦} = ran 𝑓) |
| 19 | 18 | eqeq1d 2241 |
. . . . . . . . . 10
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → ({𝑦 ∣ 𝐵𝑓𝑦} = {𝑦} ↔ ran 𝑓 = {𝑦})) |
| 20 | 19 | exbidv 1874 |
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → (∃𝑦{𝑦 ∣ 𝐵𝑓𝑦} = {𝑦} ↔ ∃𝑦ran 𝑓 = {𝑦})) |
| 21 | 11, 20 | bitrid 192 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → (∃!𝑦 𝐵𝑓𝑦 ↔ ∃𝑦ran 𝑓 = {𝑦})) |
| 22 | 10, 21 | mpbid 147 |
. . . . . . 7
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → ∃𝑦ran 𝑓 = {𝑦}) |
| 23 | | frn 5508 |
. . . . . . . . . . . . 13
⊢ (𝑓:{𝐵}⟶𝐴 → ran 𝑓 ⊆ 𝐴) |
| 24 | 23 | sseld 3236 |
. . . . . . . . . . . 12
⊢ (𝑓:{𝐵}⟶𝐴 → (𝑦 ∈ ran 𝑓 → 𝑦 ∈ 𝐴)) |
| 25 | | vsnid 3714 |
. . . . . . . . . . . . 13
⊢ 𝑦 ∈ {𝑦} |
| 26 | | eleq2 2296 |
. . . . . . . . . . . . 13
⊢ (ran
𝑓 = {𝑦} → (𝑦 ∈ ran 𝑓 ↔ 𝑦 ∈ {𝑦})) |
| 27 | 25, 26 | mpbiri 168 |
. . . . . . . . . . . 12
⊢ (ran
𝑓 = {𝑦} → 𝑦 ∈ ran 𝑓) |
| 28 | 24, 27 | impel 280 |
. . . . . . . . . . 11
⊢ ((𝑓:{𝐵}⟶𝐴 ∧ ran 𝑓 = {𝑦}) → 𝑦 ∈ 𝐴) |
| 29 | 28 | adantll 476 |
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → 𝑦 ∈ 𝐴) |
| 30 | | ffrn 5511 |
. . . . . . . . . . . . . 14
⊢ (𝑓:{𝐵}⟶𝐴 → 𝑓:{𝐵}⟶ran 𝑓) |
| 31 | | feq3 5484 |
. . . . . . . . . . . . . 14
⊢ (ran
𝑓 = {𝑦} → (𝑓:{𝐵}⟶ran 𝑓 ↔ 𝑓:{𝐵}⟶{𝑦})) |
| 32 | 30, 31 | syl5ibcom 155 |
. . . . . . . . . . . . 13
⊢ (𝑓:{𝐵}⟶𝐴 → (ran 𝑓 = {𝑦} → 𝑓:{𝐵}⟶{𝑦})) |
| 33 | 32 | imp 124 |
. . . . . . . . . . . 12
⊢ ((𝑓:{𝐵}⟶𝐴 ∧ ran 𝑓 = {𝑦}) → 𝑓:{𝐵}⟶{𝑦}) |
| 34 | 33 | adantll 476 |
. . . . . . . . . . 11
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → 𝑓:{𝐵}⟶{𝑦}) |
| 35 | 2 | ad2antrr 488 |
. . . . . . . . . . . 12
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → 𝐵 ∈ 𝑊) |
| 36 | | vex 2815 |
. . . . . . . . . . . 12
⊢ 𝑦 ∈ V |
| 37 | | fsng 5841 |
. . . . . . . . . . . 12
⊢ ((𝐵 ∈ 𝑊 ∧ 𝑦 ∈ V) → (𝑓:{𝐵}⟶{𝑦} ↔ 𝑓 = {〈𝐵, 𝑦〉})) |
| 38 | 35, 36, 37 | sylancl 413 |
. . . . . . . . . . 11
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → (𝑓:{𝐵}⟶{𝑦} ↔ 𝑓 = {〈𝐵, 𝑦〉})) |
| 39 | 34, 38 | mpbid 147 |
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → 𝑓 = {〈𝐵, 𝑦〉}) |
| 40 | 29, 39 | jca 306 |
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) ∧ ran 𝑓 = {𝑦}) → (𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉})) |
| 41 | 40 | ex 115 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → (ran 𝑓 = {𝑦} → (𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉}))) |
| 42 | 41 | eximdv 1929 |
. . . . . . 7
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → (∃𝑦ran 𝑓 = {𝑦} → ∃𝑦(𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉}))) |
| 43 | 22, 42 | mpd 13 |
. . . . . 6
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → ∃𝑦(𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉})) |
| 44 | | df-rex 2526 |
. . . . . 6
⊢
(∃𝑦 ∈
𝐴 𝑓 = {〈𝐵, 𝑦〉} ↔ ∃𝑦(𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉})) |
| 45 | 43, 44 | sylibr 134 |
. . . . 5
⊢ ((𝜑 ∧ 𝑓:{𝐵}⟶𝐴) → ∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉}) |
| 46 | 45 | ex 115 |
. . . 4
⊢ (𝜑 → (𝑓:{𝐵}⟶𝐴 → ∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉})) |
| 47 | | f1osng 5648 |
. . . . . . . . . . 11
⊢ ((𝐵 ∈ 𝑊 ∧ 𝑦 ∈ V) → {〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦}) |
| 48 | 2, 36, 47 | sylancl 413 |
. . . . . . . . . 10
⊢ (𝜑 → {〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦}) |
| 49 | 48 | adantr 276 |
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → {〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦}) |
| 50 | | f1oeq1 5593 |
. . . . . . . . . . 11
⊢ (𝑓 = {〈𝐵, 𝑦〉} → (𝑓:{𝐵}–1-1-onto→{𝑦} ↔ {〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦})) |
| 51 | 50 | bicomd 141 |
. . . . . . . . . 10
⊢ (𝑓 = {〈𝐵, 𝑦〉} → ({〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦} ↔ 𝑓:{𝐵}–1-1-onto→{𝑦})) |
| 52 | 51 | adantl 277 |
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → ({〈𝐵, 𝑦〉}:{𝐵}–1-1-onto→{𝑦} ↔ 𝑓:{𝐵}–1-1-onto→{𝑦})) |
| 53 | 49, 52 | mpbid 147 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → 𝑓:{𝐵}–1-1-onto→{𝑦}) |
| 54 | | f1of 5605 |
. . . . . . . 8
⊢ (𝑓:{𝐵}–1-1-onto→{𝑦} → 𝑓:{𝐵}⟶{𝑦}) |
| 55 | 53, 54 | syl 14 |
. . . . . . 7
⊢ ((𝜑 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → 𝑓:{𝐵}⟶{𝑦}) |
| 56 | 55 | 3adant2 1043 |
. . . . . 6
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → 𝑓:{𝐵}⟶{𝑦}) |
| 57 | | snssi 3831 |
. . . . . . 7
⊢ (𝑦 ∈ 𝐴 → {𝑦} ⊆ 𝐴) |
| 58 | 57 | 3ad2ant2 1046 |
. . . . . 6
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → {𝑦} ⊆ 𝐴) |
| 59 | 56, 58 | fssd 5513 |
. . . . 5
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴 ∧ 𝑓 = {〈𝐵, 𝑦〉}) → 𝑓:{𝐵}⟶𝐴) |
| 60 | 59 | rexlimdv3a 2662 |
. . . 4
⊢ (𝜑 → (∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉} → 𝑓:{𝐵}⟶𝐴)) |
| 61 | 46, 60 | impbid 129 |
. . 3
⊢ (𝜑 → (𝑓:{𝐵}⟶𝐴 ↔ ∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉})) |
| 62 | 5, 61 | bitrd 188 |
. 2
⊢ (𝜑 → (𝑓 ∈ (𝐴 ↑𝑚 {𝐵}) ↔ ∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉})) |
| 63 | 62 | eqabdv 2363 |
1
⊢ (𝜑 → (𝐴 ↑𝑚 {𝐵}) = {𝑓 ∣ ∃𝑦 ∈ 𝐴 𝑓 = {〈𝐵, 𝑦〉}}) |