Proof of Theorem axlowdimlem12
Step | Hyp | Ref
| Expression |
1 | | axlowdimlem10.1 |
. . 3
⊢ 𝑄 = ({〈(𝐼 + 1), 1〉} ∪ (((1...𝑁) ∖ {(𝐼 + 1)}) × {0})) |
2 | 1 | fveq1i 6757 |
. 2
⊢ (𝑄‘𝐾) = (({〈(𝐼 + 1), 1〉} ∪ (((1...𝑁) ∖ {(𝐼 + 1)}) × {0}))‘𝐾) |
3 | | eldifsn 4717 |
. . 3
⊢ (𝐾 ∈ ((1...𝑁) ∖ {(𝐼 + 1)}) ↔ (𝐾 ∈ (1...𝑁) ∧ 𝐾 ≠ (𝐼 + 1))) |
4 | | disjdif 4402 |
. . . . 5
⊢ ({(𝐼 + 1)} ∩ ((1...𝑁) ∖ {(𝐼 + 1)})) = ∅ |
5 | | ovex 7288 |
. . . . . . 7
⊢ (𝐼 + 1) ∈ V |
6 | | 1ex 10902 |
. . . . . . 7
⊢ 1 ∈
V |
7 | 5, 6 | fnsn 6476 |
. . . . . 6
⊢
{〈(𝐼 + 1),
1〉} Fn {(𝐼 +
1)} |
8 | | c0ex 10900 |
. . . . . . . 8
⊢ 0 ∈
V |
9 | 8 | fconst 6644 |
. . . . . . 7
⊢
(((1...𝑁) ∖
{(𝐼 + 1)}) ×
{0}):((1...𝑁) ∖
{(𝐼 +
1)})⟶{0} |
10 | | ffn 6584 |
. . . . . . 7
⊢
((((1...𝑁) ∖
{(𝐼 + 1)}) ×
{0}):((1...𝑁) ∖
{(𝐼 + 1)})⟶{0}
→ (((1...𝑁) ∖
{(𝐼 + 1)}) × {0}) Fn
((1...𝑁) ∖ {(𝐼 + 1)})) |
11 | 9, 10 | ax-mp 5 |
. . . . . 6
⊢
(((1...𝑁) ∖
{(𝐼 + 1)}) × {0}) Fn
((1...𝑁) ∖ {(𝐼 + 1)}) |
12 | | fvun2 6842 |
. . . . . 6
⊢
(({〈(𝐼 + 1),
1〉} Fn {(𝐼 + 1)} ∧
(((1...𝑁) ∖ {(𝐼 + 1)}) × {0}) Fn
((1...𝑁) ∖ {(𝐼 + 1)}) ∧ (({(𝐼 + 1)} ∩ ((1...𝑁) ∖ {(𝐼 + 1)})) = ∅ ∧ 𝐾 ∈ ((1...𝑁) ∖ {(𝐼 + 1)}))) → (({〈(𝐼 + 1), 1〉} ∪ (((1...𝑁) ∖ {(𝐼 + 1)}) × {0}))‘𝐾) = ((((1...𝑁) ∖ {(𝐼 + 1)}) × {0})‘𝐾)) |
13 | 7, 11, 12 | mp3an12 1449 |
. . . . 5
⊢
((({(𝐼 + 1)} ∩
((1...𝑁) ∖ {(𝐼 + 1)})) = ∅ ∧ 𝐾 ∈ ((1...𝑁) ∖ {(𝐼 + 1)})) → (({〈(𝐼 + 1), 1〉} ∪ (((1...𝑁) ∖ {(𝐼 + 1)}) × {0}))‘𝐾) = ((((1...𝑁) ∖ {(𝐼 + 1)}) × {0})‘𝐾)) |
14 | 4, 13 | mpan 686 |
. . . 4
⊢ (𝐾 ∈ ((1...𝑁) ∖ {(𝐼 + 1)}) → (({〈(𝐼 + 1), 1〉} ∪ (((1...𝑁) ∖ {(𝐼 + 1)}) × {0}))‘𝐾) = ((((1...𝑁) ∖ {(𝐼 + 1)}) × {0})‘𝐾)) |
15 | 8 | fvconst2 7061 |
. . . 4
⊢ (𝐾 ∈ ((1...𝑁) ∖ {(𝐼 + 1)}) → ((((1...𝑁) ∖ {(𝐼 + 1)}) × {0})‘𝐾) = 0) |
16 | 14, 15 | eqtrd 2778 |
. . 3
⊢ (𝐾 ∈ ((1...𝑁) ∖ {(𝐼 + 1)}) → (({〈(𝐼 + 1), 1〉} ∪ (((1...𝑁) ∖ {(𝐼 + 1)}) × {0}))‘𝐾) = 0) |
17 | 3, 16 | sylbir 234 |
. 2
⊢ ((𝐾 ∈ (1...𝑁) ∧ 𝐾 ≠ (𝐼 + 1)) → (({〈(𝐼 + 1), 1〉} ∪ (((1...𝑁) ∖ {(𝐼 + 1)}) × {0}))‘𝐾) = 0) |
18 | 2, 17 | syl5eq 2791 |
1
⊢ ((𝐾 ∈ (1...𝑁) ∧ 𝐾 ≠ (𝐼 + 1)) → (𝑄‘𝐾) = 0) |