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Mirrors > Home > ILE Home > Th. List > unssad | GIF version |
Description: If (𝐴 ∪ 𝐵) is contained in 𝐶, so is 𝐴. One-way deduction form of unss 3174. Partial converse of unssd 3176. (Contributed by David Moews, 1-May-2017.) |
Ref | Expression |
---|---|
unssad.1 | ⊢ (𝜑 → (𝐴 ∪ 𝐵) ⊆ 𝐶) |
Ref | Expression |
---|---|
unssad | ⊢ (𝜑 → 𝐴 ⊆ 𝐶) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | unssad.1 | . . 3 ⊢ (𝜑 → (𝐴 ∪ 𝐵) ⊆ 𝐶) | |
2 | unss 3174 | . . 3 ⊢ ((𝐴 ⊆ 𝐶 ∧ 𝐵 ⊆ 𝐶) ↔ (𝐴 ∪ 𝐵) ⊆ 𝐶) | |
3 | 1, 2 | sylibr 132 | . 2 ⊢ (𝜑 → (𝐴 ⊆ 𝐶 ∧ 𝐵 ⊆ 𝐶)) |
4 | 3 | simpld 110 | 1 ⊢ (𝜑 → 𝐴 ⊆ 𝐶) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 102 ∪ cun 2997 ⊆ wss 2999 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-io 665 ax-5 1381 ax-7 1382 ax-gen 1383 ax-ie1 1427 ax-ie2 1428 ax-8 1440 ax-10 1441 ax-11 1442 ax-i12 1443 ax-bndl 1444 ax-4 1445 ax-17 1464 ax-i9 1468 ax-ial 1472 ax-i5r 1473 ax-ext 2070 |
This theorem depends on definitions: df-bi 115 df-tru 1292 df-nf 1395 df-sb 1693 df-clab 2075 df-cleq 2081 df-clel 2084 df-nfc 2217 df-v 2621 df-un 3003 df-in 3005 df-ss 3012 |
This theorem is referenced by: ersym 6302 findcard2d 6605 findcard2sd 6606 diffifi 6608 sumsplitdc 10822 fsumabs 10855 fsumiun 10867 |
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