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Mirrors > Home > MPE Home > Th. List > pwssb | Structured version Visualization version GIF version |
Description: Two ways to express a collection of subclasses. (Contributed by NM, 19-Jul-2006.) |
Ref | Expression |
---|---|
pwssb | ⊢ (𝐴 ⊆ 𝒫 𝐵 ↔ ∀𝑥 ∈ 𝐴 𝑥 ⊆ 𝐵) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sspwuni 5110 | . 2 ⊢ (𝐴 ⊆ 𝒫 𝐵 ↔ ∪ 𝐴 ⊆ 𝐵) | |
2 | unissb 4949 | . 2 ⊢ (∪ 𝐴 ⊆ 𝐵 ↔ ∀𝑥 ∈ 𝐴 𝑥 ⊆ 𝐵) | |
3 | 1, 2 | bitri 274 | 1 ⊢ (𝐴 ⊆ 𝒫 𝐵 ↔ ∀𝑥 ∈ 𝐴 𝑥 ⊆ 𝐵) |
Colors of variables: wff setvar class |
Syntax hints: ↔ wb 205 ∀wral 3051 ⊆ wss 3947 𝒫 cpw 4607 ∪ cuni 4915 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1790 ax-4 1804 ax-5 1906 ax-6 1964 ax-7 2004 ax-8 2101 ax-9 2109 ax-ext 2697 |
This theorem depends on definitions: df-bi 206 df-an 395 df-tru 1537 df-ex 1775 df-sb 2061 df-clab 2704 df-cleq 2718 df-clel 2803 df-ral 3052 df-v 3464 df-ss 3964 df-pw 4609 df-uni 4916 |
This theorem is referenced by: ustuni 24225 metustfbas 24560 intlidl 33297 dmvlsiga 33964 1stmbfm 34096 2ndmbfm 34097 dya2iocucvr 34120 gneispace 43819 preimafvsspwdm 46979 |
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