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Mirrors > Home > MPE Home > Th. List > unss12 | Structured version Visualization version GIF version |
Description: Subclass law for union of classes. (Contributed by NM, 2-Jun-2004.) |
Ref | Expression |
---|---|
unss12 | ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐶 ⊆ 𝐷) → (𝐴 ∪ 𝐶) ⊆ (𝐵 ∪ 𝐷)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | unss1 4154 | . 2 ⊢ (𝐴 ⊆ 𝐵 → (𝐴 ∪ 𝐶) ⊆ (𝐵 ∪ 𝐶)) | |
2 | unss2 4156 | . 2 ⊢ (𝐶 ⊆ 𝐷 → (𝐵 ∪ 𝐶) ⊆ (𝐵 ∪ 𝐷)) | |
3 | 1, 2 | sylan9ss 3979 | 1 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐶 ⊆ 𝐷) → (𝐴 ∪ 𝐶) ⊆ (𝐵 ∪ 𝐷)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 398 ∪ cun 3933 ⊆ wss 3935 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1792 ax-4 1806 ax-5 1907 ax-6 1966 ax-7 2011 ax-8 2112 ax-9 2120 ax-10 2141 ax-11 2157 ax-12 2173 ax-ext 2793 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-tru 1536 df-ex 1777 df-nf 1781 df-sb 2066 df-clab 2800 df-cleq 2814 df-clel 2893 df-nfc 2963 df-v 3496 df-un 3940 df-in 3942 df-ss 3951 |
This theorem is referenced by: pwssun 5455 fun 6539 undom 8604 finsschain 8830 trclun 14373 relexpfld 14407 mulgfval 18225 mvdco 18572 dprd2da 19163 dmdprdsplit2lem 19166 lspun 19758 spanuni 29320 sshhococi 29322 mthmpps 32829 pibt2 34697 mblfinlem3 34930 dochdmj1 38525 mptrcllem 39971 clcnvlem 39981 dfrcl2 40017 relexpss1d 40048 corclrcl 40050 relexp0a 40059 corcltrcl 40082 frege131d 40107 |
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