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Mirrors > Home > MPE Home > Th. List > Mathboxes > fneuni | Structured version Visualization version GIF version |
Description: If 𝐵 is finer than 𝐴, every element of 𝐴 is a union of elements of 𝐵. (Contributed by Jeff Hankins, 11-Oct-2009.) |
Ref | Expression |
---|---|
fneuni | ⊢ ((𝐴Fne𝐵 ∧ 𝑆 ∈ 𝐴) → ∃𝑥(𝑥 ⊆ 𝐵 ∧ 𝑆 = ∪ 𝑥)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | fnetg 34817 | . . 3 ⊢ (𝐴Fne𝐵 → 𝐴 ⊆ (topGen‘𝐵)) | |
2 | 1 | sselda 3944 | . 2 ⊢ ((𝐴Fne𝐵 ∧ 𝑆 ∈ 𝐴) → 𝑆 ∈ (topGen‘𝐵)) |
3 | elfvdm 6879 | . . . 4 ⊢ (𝑆 ∈ (topGen‘𝐵) → 𝐵 ∈ dom topGen) | |
4 | eltg3 22312 | . . . 4 ⊢ (𝐵 ∈ dom topGen → (𝑆 ∈ (topGen‘𝐵) ↔ ∃𝑥(𝑥 ⊆ 𝐵 ∧ 𝑆 = ∪ 𝑥))) | |
5 | 3, 4 | syl 17 | . . 3 ⊢ (𝑆 ∈ (topGen‘𝐵) → (𝑆 ∈ (topGen‘𝐵) ↔ ∃𝑥(𝑥 ⊆ 𝐵 ∧ 𝑆 = ∪ 𝑥))) |
6 | 5 | ibi 266 | . 2 ⊢ (𝑆 ∈ (topGen‘𝐵) → ∃𝑥(𝑥 ⊆ 𝐵 ∧ 𝑆 = ∪ 𝑥)) |
7 | 2, 6 | syl 17 | 1 ⊢ ((𝐴Fne𝐵 ∧ 𝑆 ∈ 𝐴) → ∃𝑥(𝑥 ⊆ 𝐵 ∧ 𝑆 = ∪ 𝑥)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 205 ∧ wa 396 = wceq 1541 ∃wex 1781 ∈ wcel 2106 ⊆ wss 3910 ∪ cuni 4865 class class class wbr 5105 dom cdm 5633 ‘cfv 6496 topGenctg 17319 Fnecfne 34808 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1913 ax-6 1971 ax-7 2011 ax-8 2108 ax-9 2116 ax-10 2137 ax-11 2154 ax-12 2171 ax-ext 2707 ax-sep 5256 ax-nul 5263 ax-pow 5320 ax-pr 5384 ax-un 7672 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 846 df-3an 1089 df-tru 1544 df-fal 1554 df-ex 1782 df-nf 1786 df-sb 2068 df-mo 2538 df-eu 2567 df-clab 2714 df-cleq 2728 df-clel 2814 df-nfc 2889 df-ne 2944 df-ral 3065 df-rex 3074 df-rab 3408 df-v 3447 df-dif 3913 df-un 3915 df-in 3917 df-ss 3927 df-nul 4283 df-if 4487 df-pw 4562 df-sn 4587 df-pr 4589 df-op 4593 df-uni 4866 df-br 5106 df-opab 5168 df-mpt 5189 df-id 5531 df-xp 5639 df-rel 5640 df-cnv 5641 df-co 5642 df-dm 5643 df-iota 6448 df-fun 6498 df-fv 6504 df-topgen 17325 df-fne 34809 |
This theorem is referenced by: (None) |
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