Proof of Theorem f1o00
| Step | Hyp | Ref
| Expression |
| 1 | | dff1o4 5154 |
. 2
⊢ (𝐹:∅–1-1-onto→𝐴 ↔ (𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴)) |
| 2 | | fn0 5038 |
. . . . . 6
⊢ (𝐹 Fn ∅ ↔ 𝐹 = ∅) |
| 3 | 2 | biimpi 118 |
. . . . 5
⊢ (𝐹 Fn ∅ → 𝐹 = ∅) |
| 4 | 3 | adantr 270 |
. . . 4
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → 𝐹 = ∅) |
| 5 | | dm0 4567 |
. . . . 5
⊢ dom
∅ = ∅ |
| 6 | | cnveq 4527 |
. . . . . . . . . 10
⊢ (𝐹 = ∅ → ◡𝐹 = ◡∅) |
| 7 | | cnv0 4747 |
. . . . . . . . . 10
⊢ ◡∅ = ∅ |
| 8 | 6, 7 | syl6eq 2129 |
. . . . . . . . 9
⊢ (𝐹 = ∅ → ◡𝐹 = ∅) |
| 9 | 2, 8 | sylbi 119 |
. . . . . . . 8
⊢ (𝐹 Fn ∅ → ◡𝐹 = ∅) |
| 10 | 9 | fneq1d 5009 |
. . . . . . 7
⊢ (𝐹 Fn ∅ → (◡𝐹 Fn 𝐴 ↔ ∅ Fn 𝐴)) |
| 11 | 10 | biimpa 290 |
. . . . . 6
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → ∅ Fn 𝐴) |
| 12 | | fndm 5018 |
. . . . . 6
⊢ (∅
Fn 𝐴 → dom ∅ =
𝐴) |
| 13 | 11, 12 | syl 14 |
. . . . 5
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → dom ∅ = 𝐴) |
| 14 | 5, 13 | syl5reqr 2128 |
. . . 4
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → 𝐴 = ∅) |
| 15 | 4, 14 | jca 300 |
. . 3
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) → (𝐹 = ∅ ∧ 𝐴 = ∅)) |
| 16 | 2 | biimpri 131 |
. . . . 5
⊢ (𝐹 = ∅ → 𝐹 Fn ∅) |
| 17 | 16 | adantr 270 |
. . . 4
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → 𝐹 Fn ∅) |
| 18 | | eqid 2081 |
. . . . . 6
⊢ ∅ =
∅ |
| 19 | | fn0 5038 |
. . . . . 6
⊢ (∅
Fn ∅ ↔ ∅ = ∅) |
| 20 | 18, 19 | mpbir 144 |
. . . . 5
⊢ ∅
Fn ∅ |
| 21 | 8 | fneq1d 5009 |
. . . . . 6
⊢ (𝐹 = ∅ → (◡𝐹 Fn 𝐴 ↔ ∅ Fn 𝐴)) |
| 22 | | fneq2 5008 |
. . . . . 6
⊢ (𝐴 = ∅ → (∅ Fn
𝐴 ↔ ∅ Fn
∅)) |
| 23 | 21, 22 | sylan9bb 449 |
. . . . 5
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → (◡𝐹 Fn 𝐴 ↔ ∅ Fn
∅)) |
| 24 | 20, 23 | mpbiri 166 |
. . . 4
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → ◡𝐹 Fn 𝐴) |
| 25 | 17, 24 | jca 300 |
. . 3
⊢ ((𝐹 = ∅ ∧ 𝐴 = ∅) → (𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴)) |
| 26 | 15, 25 | impbii 124 |
. 2
⊢ ((𝐹 Fn ∅ ∧ ◡𝐹 Fn 𝐴) ↔ (𝐹 = ∅ ∧ 𝐴 = ∅)) |
| 27 | 1, 26 | bitri 182 |
1
⊢ (𝐹:∅–1-1-onto→𝐴 ↔ (𝐹 = ∅ ∧ 𝐴 = ∅)) |