Proof of Theorem fsets
Step | Hyp | Ref
| Expression |
1 | | difss 4062 |
. . . . . 6
⊢ (𝐴 ∖ {𝑋}) ⊆ 𝐴 |
2 | | fssres 6624 |
. . . . . 6
⊢ ((𝐹:𝐴⟶𝐵 ∧ (𝐴 ∖ {𝑋}) ⊆ 𝐴) → (𝐹 ↾ (𝐴 ∖ {𝑋})):(𝐴 ∖ {𝑋})⟶𝐵) |
3 | 1, 2 | mpan2 687 |
. . . . 5
⊢ (𝐹:𝐴⟶𝐵 → (𝐹 ↾ (𝐴 ∖ {𝑋})):(𝐴 ∖ {𝑋})⟶𝐵) |
4 | | ffn 6584 |
. . . . . . . . 9
⊢ (𝐹:𝐴⟶𝐵 → 𝐹 Fn 𝐴) |
5 | | fnresdm 6535 |
. . . . . . . . 9
⊢ (𝐹 Fn 𝐴 → (𝐹 ↾ 𝐴) = 𝐹) |
6 | 4, 5 | syl 17 |
. . . . . . . 8
⊢ (𝐹:𝐴⟶𝐵 → (𝐹 ↾ 𝐴) = 𝐹) |
7 | 6 | reseq1d 5879 |
. . . . . . 7
⊢ (𝐹:𝐴⟶𝐵 → ((𝐹 ↾ 𝐴) ↾ (V ∖ {𝑋})) = (𝐹 ↾ (V ∖ {𝑋}))) |
8 | | resres 5893 |
. . . . . . . 8
⊢ ((𝐹 ↾ 𝐴) ↾ (V ∖ {𝑋})) = (𝐹 ↾ (𝐴 ∩ (V ∖ {𝑋}))) |
9 | | invdif 4199 |
. . . . . . . . 9
⊢ (𝐴 ∩ (V ∖ {𝑋})) = (𝐴 ∖ {𝑋}) |
10 | 9 | reseq2i 5877 |
. . . . . . . 8
⊢ (𝐹 ↾ (𝐴 ∩ (V ∖ {𝑋}))) = (𝐹 ↾ (𝐴 ∖ {𝑋})) |
11 | 8, 10 | eqtri 2766 |
. . . . . . 7
⊢ ((𝐹 ↾ 𝐴) ↾ (V ∖ {𝑋})) = (𝐹 ↾ (𝐴 ∖ {𝑋})) |
12 | 7, 11 | eqtr3di 2794 |
. . . . . 6
⊢ (𝐹:𝐴⟶𝐵 → (𝐹 ↾ (V ∖ {𝑋})) = (𝐹 ↾ (𝐴 ∖ {𝑋}))) |
13 | 12 | feq1d 6569 |
. . . . 5
⊢ (𝐹:𝐴⟶𝐵 → ((𝐹 ↾ (V ∖ {𝑋})):(𝐴 ∖ {𝑋})⟶𝐵 ↔ (𝐹 ↾ (𝐴 ∖ {𝑋})):(𝐴 ∖ {𝑋})⟶𝐵)) |
14 | 3, 13 | mpbird 256 |
. . . 4
⊢ (𝐹:𝐴⟶𝐵 → (𝐹 ↾ (V ∖ {𝑋})):(𝐴 ∖ {𝑋})⟶𝐵) |
15 | 14 | adantl 481 |
. . 3
⊢ ((𝐹 ∈ 𝑉 ∧ 𝐹:𝐴⟶𝐵) → (𝐹 ↾ (V ∖ {𝑋})):(𝐴 ∖ {𝑋})⟶𝐵) |
16 | | fsnunf2 7040 |
. . 3
⊢ (((𝐹 ↾ (V ∖ {𝑋})):(𝐴 ∖ {𝑋})⟶𝐵 ∧ 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵) → ((𝐹 ↾ (V ∖ {𝑋})) ∪ {〈𝑋, 𝑌〉}):𝐴⟶𝐵) |
17 | 15, 16 | syl3an1 1161 |
. 2
⊢ (((𝐹 ∈ 𝑉 ∧ 𝐹:𝐴⟶𝐵) ∧ 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵) → ((𝐹 ↾ (V ∖ {𝑋})) ∪ {〈𝑋, 𝑌〉}):𝐴⟶𝐵) |
18 | | simp1l 1195 |
. . 3
⊢ (((𝐹 ∈ 𝑉 ∧ 𝐹:𝐴⟶𝐵) ∧ 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵) → 𝐹 ∈ 𝑉) |
19 | | simp3 1136 |
. . 3
⊢ (((𝐹 ∈ 𝑉 ∧ 𝐹:𝐴⟶𝐵) ∧ 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵) → 𝑌 ∈ 𝐵) |
20 | | setsval 16796 |
. . . 4
⊢ ((𝐹 ∈ 𝑉 ∧ 𝑌 ∈ 𝐵) → (𝐹 sSet 〈𝑋, 𝑌〉) = ((𝐹 ↾ (V ∖ {𝑋})) ∪ {〈𝑋, 𝑌〉})) |
21 | 20 | feq1d 6569 |
. . 3
⊢ ((𝐹 ∈ 𝑉 ∧ 𝑌 ∈ 𝐵) → ((𝐹 sSet 〈𝑋, 𝑌〉):𝐴⟶𝐵 ↔ ((𝐹 ↾ (V ∖ {𝑋})) ∪ {〈𝑋, 𝑌〉}):𝐴⟶𝐵)) |
22 | 18, 19, 21 | syl2anc 583 |
. 2
⊢ (((𝐹 ∈ 𝑉 ∧ 𝐹:𝐴⟶𝐵) ∧ 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵) → ((𝐹 sSet 〈𝑋, 𝑌〉):𝐴⟶𝐵 ↔ ((𝐹 ↾ (V ∖ {𝑋})) ∪ {〈𝑋, 𝑌〉}):𝐴⟶𝐵)) |
23 | 17, 22 | mpbird 256 |
1
⊢ (((𝐹 ∈ 𝑉 ∧ 𝐹:𝐴⟶𝐵) ∧ 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵) → (𝐹 sSet 〈𝑋, 𝑌〉):𝐴⟶𝐵) |