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Mirrors > Home > MPE Home > Th. List > intss1 | Structured version Visualization version GIF version |
Description: An element of a class includes the intersection of the class. Exercise 4 of [TakeutiZaring] p. 44 (with correction), generalized to classes. (Contributed by NM, 18-Nov-1995.) |
Ref | Expression |
---|---|
intss1 | ⊢ (𝐴 ∈ 𝐵 → ∩ 𝐵 ⊆ 𝐴) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | vex 3479 | . . . 4 ⊢ 𝑥 ∈ V | |
2 | 1 | elint 4957 | . . 3 ⊢ (𝑥 ∈ ∩ 𝐵 ↔ ∀𝑦(𝑦 ∈ 𝐵 → 𝑥 ∈ 𝑦)) |
3 | eleq1 2822 | . . . . . 6 ⊢ (𝑦 = 𝐴 → (𝑦 ∈ 𝐵 ↔ 𝐴 ∈ 𝐵)) | |
4 | eleq2 2823 | . . . . . 6 ⊢ (𝑦 = 𝐴 → (𝑥 ∈ 𝑦 ↔ 𝑥 ∈ 𝐴)) | |
5 | 3, 4 | imbi12d 345 | . . . . 5 ⊢ (𝑦 = 𝐴 → ((𝑦 ∈ 𝐵 → 𝑥 ∈ 𝑦) ↔ (𝐴 ∈ 𝐵 → 𝑥 ∈ 𝐴))) |
6 | 5 | spcgv 3587 | . . . 4 ⊢ (𝐴 ∈ 𝐵 → (∀𝑦(𝑦 ∈ 𝐵 → 𝑥 ∈ 𝑦) → (𝐴 ∈ 𝐵 → 𝑥 ∈ 𝐴))) |
7 | 6 | pm2.43a 54 | . . 3 ⊢ (𝐴 ∈ 𝐵 → (∀𝑦(𝑦 ∈ 𝐵 → 𝑥 ∈ 𝑦) → 𝑥 ∈ 𝐴)) |
8 | 2, 7 | biimtrid 241 | . 2 ⊢ (𝐴 ∈ 𝐵 → (𝑥 ∈ ∩ 𝐵 → 𝑥 ∈ 𝐴)) |
9 | 8 | ssrdv 3989 | 1 ⊢ (𝐴 ∈ 𝐵 → ∩ 𝐵 ⊆ 𝐴) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∀wal 1540 = wceq 1542 ∈ wcel 2107 ⊆ wss 3949 ∩ cint 4951 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2109 ax-9 2117 ax-ext 2704 |
This theorem depends on definitions: df-bi 206 df-an 398 df-tru 1545 df-ex 1783 df-sb 2069 df-clab 2711 df-cleq 2725 df-clel 2811 df-v 3477 df-in 3956 df-ss 3966 df-int 4952 |
This theorem is referenced by: intminss 4979 intmin3 4981 intab 4983 int0el 4984 trintss 5285 intex 5338 intidg 5458 oneqmini 6417 sorpssint 7723 onint 7778 onssmin 7780 onnmin 7786 nnawordex 8637 cofon1 8671 cofonr 8673 dffi2 9418 inficl 9420 dffi3 9426 tcmin 9736 tc2 9737 rankr1ai 9793 rankuni2b 9848 tcrank 9879 harval2 9992 cfflb 10254 fin23lem20 10332 fin23lem38 10344 isf32lem2 10349 intwun 10730 inttsk 10769 intgru 10809 dfnn2 12225 dfuzi 12653 trclubi 14943 trclubgi 14944 trclub 14945 trclubg 14946 cotrtrclfv 14959 trclun 14961 dfrtrcl2 15009 mremre 17548 isacs1i 17601 mrelatglb 18513 cycsubg 19085 efgrelexlemb 19618 efgcpbllemb 19623 frgpuplem 19640 primefld 20421 cssmre 21246 toponmre 22597 1stcfb 22949 ptcnplem 23125 fbssfi 23341 uffix 23425 ufildom1 23430 alexsublem 23548 alexsubALTlem4 23554 tmdgsum2 23600 bcth3 24848 limciun 25411 aalioulem3 25847 sltval2 27159 sltres 27165 nocvxminlem 27279 eqscut2 27307 scutun12 27311 scutbdaybnd 27316 scutbdaybnd2 27317 scutbdaylt 27319 madebdaylemlrcut 27393 cofcut1 27407 cofcutr 27411 shintcli 30582 shsval2i 30640 ococin 30661 chsupsn 30666 fldgensdrg 32404 fldgenssv 32405 fldgenssp 32408 insiga 33135 ldsysgenld 33158 ldgenpisyslem2 33162 mclsssvlem 34553 mclsax 34560 mclsind 34561 untint 34681 dfon2lem8 34762 dfon2lem9 34763 clsint2 35214 topmeet 35249 topjoin 35250 heibor1lem 36677 ismrcd1 41436 mzpincl 41472 mzpf 41474 mzpindd 41484 rgspnmin 41913 onintunirab 41976 oninfint 41985 clublem 42361 dftrcl3 42471 brtrclfv2 42478 dfrtrcl3 42484 intsaluni 45045 intsal 45046 salgenss 45052 salgencntex 45059 intubeu 47609 |
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