Proof of Theorem f1o00
Step | Hyp | Ref
| Expression |
1 | | dff1o4 5450 |
. 2
⊢ (𝐹:∅–1-1-onto→𝐴 ↔ (𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴)) |
2 | | fn0 5317 |
. . . . . 6
⊢ (𝐹 Fn ∅ ↔ 𝐹 = ∅) |
3 | 2 | biimpi 119 |
. . . . 5
⊢ (𝐹 Fn ∅ → 𝐹 = ∅) |
4 | 3 | adantr 274 |
. . . 4
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → 𝐹 = ∅) |
5 | | cnveq 4785 |
. . . . . . . . . 10
⊢ (𝐹 = ∅ → ◡𝐹 = ◡∅) |
6 | | cnv0 5014 |
. . . . . . . . . 10
⊢ ◡∅ = ∅ |
7 | 5, 6 | eqtrdi 2219 |
. . . . . . . . 9
⊢ (𝐹 = ∅ → ◡𝐹 = ∅) |
8 | 2, 7 | sylbi 120 |
. . . . . . . 8
⊢ (𝐹 Fn ∅ → ◡𝐹 = ∅) |
9 | 8 | fneq1d 5288 |
. . . . . . 7
⊢ (𝐹 Fn ∅ → (◡𝐹 Fn 𝐴 ↔ ∅ Fn 𝐴)) |
10 | 9 | biimpa 294 |
. . . . . 6
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → ∅ Fn 𝐴) |
11 | | fndm 5297 |
. . . . . 6
⊢ (∅
Fn 𝐴 → dom ∅ =
𝐴) |
12 | 10, 11 | syl 14 |
. . . . 5
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → dom ∅ = 𝐴) |
13 | | dm0 4825 |
. . . . 5
⊢ dom
∅ = ∅ |
14 | 12, 13 | eqtr3di 2218 |
. . . 4
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → 𝐴 = ∅) |
15 | 4, 14 | jca 304 |
. . 3
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → (𝐹 = ∅ ∧ 𝐴 = ∅)) |
16 | 2 | biimpri 132 |
. . . . 5
⊢ (𝐹 = ∅ → 𝐹 Fn ∅) |
17 | 16 | adantr 274 |
. . . 4
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → 𝐹 Fn ∅) |
18 | | eqid 2170 |
. . . . . 6
⊢ ∅ =
∅ |
19 | | fn0 5317 |
. . . . . 6
⊢ (∅
Fn ∅ ↔ ∅ = ∅) |
20 | 18, 19 | mpbir 145 |
. . . . 5
⊢ ∅
Fn ∅ |
21 | 7 | fneq1d 5288 |
. . . . . 6
⊢ (𝐹 = ∅ → (◡𝐹 Fn 𝐴 ↔ ∅ Fn 𝐴)) |
22 | | fneq2 5287 |
. . . . . 6
⊢ (𝐴 = ∅ → (∅ Fn
𝐴 ↔ ∅ Fn
∅)) |
23 | 21, 22 | sylan9bb 459 |
. . . . 5
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → (◡𝐹 Fn 𝐴 ↔ ∅ Fn
∅)) |
24 | 20, 23 | mpbiri 167 |
. . . 4
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → ◡𝐹 Fn 𝐴) |
25 | 17, 24 | jca 304 |
. . 3
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → (𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴)) |
26 | 15, 25 | impbii 125 |
. 2
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) ↔ (𝐹 = ∅ ∧ 𝐴 = ∅)) |
27 | 1, 26 | bitri 183 |
1
⊢ (𝐹:∅–1-1-onto→𝐴 ↔ (𝐹 = ∅ ∧ 𝐴 = ∅)) |