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Mirrors > Home > ILE Home > Th. List > ssiun2s | GIF version |
Description: Subset relationship for an indexed union. (Contributed by NM, 26-Oct-2003.) |
Ref | Expression |
---|---|
ssiun2s.1 | ⊢ (𝑥 = 𝐶 → 𝐵 = 𝐷) |
Ref | Expression |
---|---|
ssiun2s | ⊢ (𝐶 ∈ 𝐴 → 𝐷 ⊆ ∪ 𝑥 ∈ 𝐴 𝐵) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nfcv 2281 | . 2 ⊢ Ⅎ𝑥𝐶 | |
2 | nfcv 2281 | . . 3 ⊢ Ⅎ𝑥𝐷 | |
3 | nfiu1 3843 | . . 3 ⊢ Ⅎ𝑥∪ 𝑥 ∈ 𝐴 𝐵 | |
4 | 2, 3 | nfss 3090 | . 2 ⊢ Ⅎ𝑥 𝐷 ⊆ ∪ 𝑥 ∈ 𝐴 𝐵 |
5 | ssiun2s.1 | . . 3 ⊢ (𝑥 = 𝐶 → 𝐵 = 𝐷) | |
6 | 5 | sseq1d 3126 | . 2 ⊢ (𝑥 = 𝐶 → (𝐵 ⊆ ∪ 𝑥 ∈ 𝐴 𝐵 ↔ 𝐷 ⊆ ∪ 𝑥 ∈ 𝐴 𝐵)) |
7 | ssiun2 3856 | . 2 ⊢ (𝑥 ∈ 𝐴 → 𝐵 ⊆ ∪ 𝑥 ∈ 𝐴 𝐵) | |
8 | 1, 4, 6, 7 | vtoclgaf 2751 | 1 ⊢ (𝐶 ∈ 𝐴 → 𝐷 ⊆ ∪ 𝑥 ∈ 𝐴 𝐵) |
Colors of variables: wff set class |
Syntax hints: → wi 4 = wceq 1331 ∈ wcel 1480 ⊆ wss 3071 ∪ ciun 3813 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-io 698 ax-5 1423 ax-7 1424 ax-gen 1425 ax-ie1 1469 ax-ie2 1470 ax-8 1482 ax-10 1483 ax-11 1484 ax-i12 1485 ax-bndl 1486 ax-4 1487 ax-17 1506 ax-i9 1510 ax-ial 1514 ax-i5r 1515 ax-ext 2121 |
This theorem depends on definitions: df-bi 116 df-tru 1334 df-nf 1437 df-sb 1736 df-clab 2126 df-cleq 2132 df-clel 2135 df-nfc 2270 df-ral 2421 df-rex 2422 df-v 2688 df-in 3077 df-ss 3084 df-iun 3815 |
This theorem is referenced by: (None) |
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