Proof of Theorem f1o00
| Step | Hyp | Ref
| Expression |
| 1 | | dff1o4 5512 |
. 2
⊢ (𝐹:∅–1-1-onto→𝐴 ↔ (𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴)) |
| 2 | | fn0 5377 |
. . . . . 6
⊢ (𝐹 Fn ∅ ↔ 𝐹 = ∅) |
| 3 | 2 | biimpi 120 |
. . . . 5
⊢ (𝐹 Fn ∅ → 𝐹 = ∅) |
| 4 | 3 | adantr 276 |
. . . 4
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → 𝐹 = ∅) |
| 5 | | cnveq 4840 |
. . . . . . . . . 10
⊢ (𝐹 = ∅ → ◡𝐹 = ◡∅) |
| 6 | | cnv0 5073 |
. . . . . . . . . 10
⊢ ◡∅ = ∅ |
| 7 | 5, 6 | eqtrdi 2245 |
. . . . . . . . 9
⊢ (𝐹 = ∅ → ◡𝐹 = ∅) |
| 8 | 2, 7 | sylbi 121 |
. . . . . . . 8
⊢ (𝐹 Fn ∅ → ◡𝐹 = ∅) |
| 9 | 8 | fneq1d 5348 |
. . . . . . 7
⊢ (𝐹 Fn ∅ → (◡𝐹 Fn 𝐴 ↔ ∅ Fn 𝐴)) |
| 10 | 9 | biimpa 296 |
. . . . . 6
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → ∅ Fn 𝐴) |
| 11 | | fndm 5357 |
. . . . . 6
⊢ (∅
Fn 𝐴 → dom ∅ =
𝐴) |
| 12 | 10, 11 | syl 14 |
. . . . 5
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → dom ∅ = 𝐴) |
| 13 | | dm0 4880 |
. . . . 5
⊢ dom
∅ = ∅ |
| 14 | 12, 13 | eqtr3di 2244 |
. . . 4
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → 𝐴 = ∅) |
| 15 | 4, 14 | jca 306 |
. . 3
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → (𝐹 = ∅ ∧ 𝐴 = ∅)) |
| 16 | 2 | biimpri 133 |
. . . . 5
⊢ (𝐹 = ∅ → 𝐹 Fn ∅) |
| 17 | 16 | adantr 276 |
. . . 4
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → 𝐹 Fn ∅) |
| 18 | | eqid 2196 |
. . . . . 6
⊢ ∅ =
∅ |
| 19 | | fn0 5377 |
. . . . . 6
⊢ (∅
Fn ∅ ↔ ∅ = ∅) |
| 20 | 18, 19 | mpbir 146 |
. . . . 5
⊢ ∅
Fn ∅ |
| 21 | 7 | fneq1d 5348 |
. . . . . 6
⊢ (𝐹 = ∅ → (◡𝐹 Fn 𝐴 ↔ ∅ Fn 𝐴)) |
| 22 | | fneq2 5347 |
. . . . . 6
⊢ (𝐴 = ∅ → (∅ Fn
𝐴 ↔ ∅ Fn
∅)) |
| 23 | 21, 22 | sylan9bb 462 |
. . . . 5
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → (◡𝐹 Fn 𝐴 ↔ ∅ Fn
∅)) |
| 24 | 20, 23 | mpbiri 168 |
. . . 4
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → ◡𝐹 Fn 𝐴) |
| 25 | 17, 24 | jca 306 |
. . 3
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → (𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴)) |
| 26 | 15, 25 | impbii 126 |
. 2
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) ↔ (𝐹 = ∅ ∧ 𝐴 = ∅)) |
| 27 | 1, 26 | bitri 184 |
1
⊢ (𝐹:∅–1-1-onto→𝐴 ↔ (𝐹 = ∅ ∧ 𝐴 = ∅)) |