Step | Hyp | Ref
| Expression |
1 | | ssid 3939 |
. . . . . . . 8
⊢ 𝑦 ⊆ 𝑦 |
2 | | sseq2 3943 |
. . . . . . . . 9
⊢ (𝑧 = 𝑦 → (𝑦 ⊆ 𝑧 ↔ 𝑦 ⊆ 𝑦)) |
3 | 2 | rspcev 3552 |
. . . . . . . 8
⊢ ((𝑦 ∈ 𝑥 ∧ 𝑦 ⊆ 𝑦) → ∃𝑧 ∈ 𝑥 𝑦 ⊆ 𝑧) |
4 | 1, 3 | mpan2 687 |
. . . . . . 7
⊢ (𝑦 ∈ 𝑥 → ∃𝑧 ∈ 𝑥 𝑦 ⊆ 𝑧) |
5 | | vex 3426 |
. . . . . . . . 9
⊢ 𝑦 ∈ V |
6 | 5 | elima 5963 |
. . . . . . . 8
⊢ (𝑦 ∈ (◡ SSet “
𝑥) ↔ ∃𝑧 ∈ 𝑥 𝑧◡ SSet 𝑦) |
7 | | vex 3426 |
. . . . . . . . . . 11
⊢ 𝑧 ∈ V |
8 | 7, 5 | brcnv 5780 |
. . . . . . . . . 10
⊢ (𝑧◡ SSet 𝑦 ↔ 𝑦 SSet 𝑧) |
9 | 7 | brsset 34118 |
. . . . . . . . . 10
⊢ (𝑦 SSet
𝑧 ↔ 𝑦 ⊆ 𝑧) |
10 | 8, 9 | bitri 274 |
. . . . . . . . 9
⊢ (𝑧◡ SSet 𝑦 ↔ 𝑦 ⊆ 𝑧) |
11 | 10 | rexbii 3177 |
. . . . . . . 8
⊢
(∃𝑧 ∈
𝑥 𝑧◡ SSet 𝑦 ↔ ∃𝑧 ∈ 𝑥 𝑦 ⊆ 𝑧) |
12 | 6, 11 | bitri 274 |
. . . . . . 7
⊢ (𝑦 ∈ (◡ SSet “
𝑥) ↔ ∃𝑧 ∈ 𝑥 𝑦 ⊆ 𝑧) |
13 | 4, 12 | sylibr 233 |
. . . . . 6
⊢ (𝑦 ∈ 𝑥 → 𝑦 ∈ (◡ SSet “
𝑥)) |
14 | 13 | ssriv 3921 |
. . . . 5
⊢ 𝑥 ⊆ (◡ SSet “
𝑥) |
15 | | sseq2 3943 |
. . . . 5
⊢ (𝑦 = (◡ SSet “
𝑥) → (𝑥 ⊆ 𝑦 ↔ 𝑥 ⊆ (◡ SSet “
𝑥))) |
16 | 14, 15 | mpbiri 257 |
. . . 4
⊢ (𝑦 = (◡ SSet “
𝑥) → 𝑥 ⊆ 𝑦) |
17 | | vex 3426 |
. . . . . 6
⊢ 𝑥 ∈ V |
18 | 17, 5 | brimage 34155 |
. . . . 5
⊢ (𝑥Image◡ SSet 𝑦 ↔ 𝑦 = (◡ SSet “
𝑥)) |
19 | | df-br 5071 |
. . . . 5
⊢ (𝑥Image◡ SSet 𝑦 ↔ 〈𝑥, 𝑦〉 ∈ Image◡ SSet
) |
20 | 18, 19 | bitr3i 276 |
. . . 4
⊢ (𝑦 = (◡ SSet “
𝑥) ↔ 〈𝑥, 𝑦〉 ∈ Image◡ SSet
) |
21 | 5 | brsset 34118 |
. . . . 5
⊢ (𝑥 SSet
𝑦 ↔ 𝑥 ⊆ 𝑦) |
22 | | df-br 5071 |
. . . . 5
⊢ (𝑥 SSet
𝑦 ↔ 〈𝑥, 𝑦〉 ∈ SSet
) |
23 | 21, 22 | bitr3i 276 |
. . . 4
⊢ (𝑥 ⊆ 𝑦 ↔ 〈𝑥, 𝑦〉 ∈ SSet
) |
24 | 16, 20, 23 | 3imtr3i 290 |
. . 3
⊢
(〈𝑥, 𝑦〉 ∈ Image◡ SSet →
〈𝑥, 𝑦〉 ∈ SSet
) |
25 | 24 | gen2 1800 |
. 2
⊢
∀𝑥∀𝑦(〈𝑥, 𝑦〉 ∈ Image◡ SSet →
〈𝑥, 𝑦〉 ∈ SSet
) |
26 | | funimage 34157 |
. . 3
⊢ Fun
Image◡ SSet
|
27 | | funrel 6435 |
. . 3
⊢ (Fun
Image◡ SSet
→ Rel Image◡ SSet ) |
28 | | ssrel 5683 |
. . 3
⊢ (Rel
Image◡ SSet
→ (Image◡ SSet ⊆ SSet
↔ ∀𝑥∀𝑦(〈𝑥, 𝑦〉 ∈ Image◡ SSet →
〈𝑥, 𝑦〉 ∈ SSet
))) |
29 | 26, 27, 28 | mp2b 10 |
. 2
⊢
(Image◡
SSet ⊆ SSet ↔ ∀𝑥∀𝑦(〈𝑥, 𝑦〉 ∈ Image◡ SSet →
〈𝑥, 𝑦〉 ∈ SSet
)) |
30 | 25, 29 | mpbir 230 |
1
⊢
Image◡
SSet ⊆ SSet |