Proof of Theorem f1omvdmvd
Step | Hyp | Ref
| Expression |
1 | | simpr 486 |
. . . . 5
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → 𝑋 ∈ dom (𝐹 ∖ I )) |
2 | | f1ofn 6780 |
. . . . . 6
⊢ (𝐹:𝐴–1-1-onto→𝐴 → 𝐹 Fn 𝐴) |
3 | | difss 4089 |
. . . . . . . . 9
⊢ (𝐹 ∖ I ) ⊆ 𝐹 |
4 | | dmss 5854 |
. . . . . . . . 9
⊢ ((𝐹 ∖ I ) ⊆ 𝐹 → dom (𝐹 ∖ I ) ⊆ dom 𝐹) |
5 | 3, 4 | ax-mp 5 |
. . . . . . . 8
⊢ dom
(𝐹 ∖ I ) ⊆ dom
𝐹 |
6 | | f1odm 6783 |
. . . . . . . 8
⊢ (𝐹:𝐴–1-1-onto→𝐴 → dom 𝐹 = 𝐴) |
7 | 5, 6 | sseqtrid 3994 |
. . . . . . 7
⊢ (𝐹:𝐴–1-1-onto→𝐴 → dom (𝐹 ∖ I ) ⊆ 𝐴) |
8 | 7 | sselda 3942 |
. . . . . 6
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → 𝑋 ∈ 𝐴) |
9 | | fnelnfp 7117 |
. . . . . 6
⊢ ((𝐹 Fn 𝐴 ∧ 𝑋 ∈ 𝐴) → (𝑋 ∈ dom (𝐹 ∖ I ) ↔ (𝐹‘𝑋) ≠ 𝑋)) |
10 | 2, 8, 9 | syl2an2r 683 |
. . . . 5
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → (𝑋 ∈ dom (𝐹 ∖ I ) ↔ (𝐹‘𝑋) ≠ 𝑋)) |
11 | 1, 10 | mpbid 231 |
. . . 4
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → (𝐹‘𝑋) ≠ 𝑋) |
12 | | f1of1 6778 |
. . . . . . 7
⊢ (𝐹:𝐴–1-1-onto→𝐴 → 𝐹:𝐴–1-1→𝐴) |
13 | 12 | adantr 482 |
. . . . . 6
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → 𝐹:𝐴–1-1→𝐴) |
14 | | f1of 6779 |
. . . . . . . 8
⊢ (𝐹:𝐴–1-1-onto→𝐴 → 𝐹:𝐴⟶𝐴) |
15 | 14 | adantr 482 |
. . . . . . 7
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → 𝐹:𝐴⟶𝐴) |
16 | 15, 8 | ffvelcdmd 7030 |
. . . . . 6
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → (𝐹‘𝑋) ∈ 𝐴) |
17 | | f1fveq 7203 |
. . . . . 6
⊢ ((𝐹:𝐴–1-1→𝐴 ∧ ((𝐹‘𝑋) ∈ 𝐴 ∧ 𝑋 ∈ 𝐴)) → ((𝐹‘(𝐹‘𝑋)) = (𝐹‘𝑋) ↔ (𝐹‘𝑋) = 𝑋)) |
18 | 13, 16, 8, 17 | syl12anc 835 |
. . . . 5
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → ((𝐹‘(𝐹‘𝑋)) = (𝐹‘𝑋) ↔ (𝐹‘𝑋) = 𝑋)) |
19 | 18 | necon3bid 2986 |
. . . 4
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → ((𝐹‘(𝐹‘𝑋)) ≠ (𝐹‘𝑋) ↔ (𝐹‘𝑋) ≠ 𝑋)) |
20 | 11, 19 | mpbird 257 |
. . 3
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → (𝐹‘(𝐹‘𝑋)) ≠ (𝐹‘𝑋)) |
21 | | fnelnfp 7117 |
. . . 4
⊢ ((𝐹 Fn 𝐴 ∧ (𝐹‘𝑋) ∈ 𝐴) → ((𝐹‘𝑋) ∈ dom (𝐹 ∖ I ) ↔ (𝐹‘(𝐹‘𝑋)) ≠ (𝐹‘𝑋))) |
22 | 2, 16, 21 | syl2an2r 683 |
. . 3
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → ((𝐹‘𝑋) ∈ dom (𝐹 ∖ I ) ↔ (𝐹‘(𝐹‘𝑋)) ≠ (𝐹‘𝑋))) |
23 | 20, 22 | mpbird 257 |
. 2
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → (𝐹‘𝑋) ∈ dom (𝐹 ∖ I )) |
24 | | eldifsn 4745 |
. 2
⊢ ((𝐹‘𝑋) ∈ (dom (𝐹 ∖ I ) ∖ {𝑋}) ↔ ((𝐹‘𝑋) ∈ dom (𝐹 ∖ I ) ∧ (𝐹‘𝑋) ≠ 𝑋)) |
25 | 23, 11, 24 | sylanbrc 584 |
1
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝑋 ∈ dom (𝐹 ∖ I )) → (𝐹‘𝑋) ∈ (dom (𝐹 ∖ I ) ∖ {𝑋})) |