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Mirrors > Home > ILE Home > Th. List > intid | GIF version |
Description: The intersection of all sets to which a set belongs is the singleton of that set. (Contributed by NM, 5-Jun-2009.) |
Ref | Expression |
---|---|
intid.1 | ⊢ 𝐴 ∈ V |
Ref | Expression |
---|---|
intid | ⊢ ∩ {𝑥 ∣ 𝐴 ∈ 𝑥} = {𝐴} |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | intid.1 | . . . 4 ⊢ 𝐴 ∈ V | |
2 | 1 | snex 4026 | . . 3 ⊢ {𝐴} ∈ V |
3 | eleq2 2152 | . . . 4 ⊢ (𝑥 = {𝐴} → (𝐴 ∈ 𝑥 ↔ 𝐴 ∈ {𝐴})) | |
4 | 1 | snid 3479 | . . . 4 ⊢ 𝐴 ∈ {𝐴} |
5 | 3, 4 | intmin3 3721 | . . 3 ⊢ ({𝐴} ∈ V → ∩ {𝑥 ∣ 𝐴 ∈ 𝑥} ⊆ {𝐴}) |
6 | 2, 5 | ax-mp 7 | . 2 ⊢ ∩ {𝑥 ∣ 𝐴 ∈ 𝑥} ⊆ {𝐴} |
7 | 1 | elintab 3705 | . . . 4 ⊢ (𝐴 ∈ ∩ {𝑥 ∣ 𝐴 ∈ 𝑥} ↔ ∀𝑥(𝐴 ∈ 𝑥 → 𝐴 ∈ 𝑥)) |
8 | id 19 | . . . 4 ⊢ (𝐴 ∈ 𝑥 → 𝐴 ∈ 𝑥) | |
9 | 7, 8 | mpgbir 1388 | . . 3 ⊢ 𝐴 ∈ ∩ {𝑥 ∣ 𝐴 ∈ 𝑥} |
10 | snssi 3587 | . . 3 ⊢ (𝐴 ∈ ∩ {𝑥 ∣ 𝐴 ∈ 𝑥} → {𝐴} ⊆ ∩ {𝑥 ∣ 𝐴 ∈ 𝑥}) | |
11 | 9, 10 | ax-mp 7 | . 2 ⊢ {𝐴} ⊆ ∩ {𝑥 ∣ 𝐴 ∈ 𝑥} |
12 | 6, 11 | eqssi 3042 | 1 ⊢ ∩ {𝑥 ∣ 𝐴 ∈ 𝑥} = {𝐴} |
Colors of variables: wff set class |
Syntax hints: → wi 4 = wceq 1290 ∈ wcel 1439 {cab 2075 Vcvv 2620 ⊆ wss 3000 {csn 3450 ∩ cint 3694 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-io 666 ax-5 1382 ax-7 1383 ax-gen 1384 ax-ie1 1428 ax-ie2 1429 ax-8 1441 ax-10 1442 ax-11 1443 ax-i12 1444 ax-bndl 1445 ax-4 1446 ax-14 1451 ax-17 1465 ax-i9 1469 ax-ial 1473 ax-i5r 1474 ax-ext 2071 ax-sep 3963 ax-pow 4015 |
This theorem depends on definitions: df-bi 116 df-tru 1293 df-nf 1396 df-sb 1694 df-clab 2076 df-cleq 2082 df-clel 2085 df-nfc 2218 df-v 2622 df-in 3006 df-ss 3013 df-pw 3435 df-sn 3456 df-int 3695 |
This theorem is referenced by: (None) |
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