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Mirrors > Home > MPE Home > Th. List > elsn | Structured version Visualization version GIF version |
Description: There is exactly one element in a singleton. Exercise 2 of [TakeutiZaring] p. 15. (Contributed by NM, 13-Sep-1995.) |
Ref | Expression |
---|---|
elsn.1 | ⊢ 𝐴 ∈ V |
Ref | Expression |
---|---|
elsn | ⊢ (𝐴 ∈ {𝐵} ↔ 𝐴 = 𝐵) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elsn.1 | . 2 ⊢ 𝐴 ∈ V | |
2 | elsng 4581 | . 2 ⊢ (𝐴 ∈ V → (𝐴 ∈ {𝐵} ↔ 𝐴 = 𝐵)) | |
3 | 1, 2 | ax-mp 5 | 1 ⊢ (𝐴 ∈ {𝐵} ↔ 𝐴 = 𝐵) |
Colors of variables: wff setvar class |
Syntax hints: ↔ wb 208 = wceq 1537 ∈ wcel 2114 Vcvv 3494 {csn 4567 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2116 ax-9 2124 ax-10 2145 ax-11 2161 ax-12 2177 ax-ext 2793 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-tru 1540 df-ex 1781 df-nf 1785 df-sb 2070 df-clab 2800 df-cleq 2814 df-clel 2893 df-nfc 2963 df-sn 4568 |
This theorem is referenced by: velsn 4583 opthwiener 5404 opthprc 5616 dmsnn0 6064 dmsnopg 6070 cnvcnvsn 6076 snsn0non 6309 funconstss 6826 fniniseg 6830 fniniseg2 6832 fsn 6897 fconstfv 6975 eusvobj2 7149 fnse 7827 wfrlem14 7968 fisn 8891 axdc3lem4 9875 axdc4lem 9877 axcclem 9879 opelreal 10552 seqid3 13415 seqz 13419 1exp 13459 hashf1lem2 13815 fprodn0f 15345 imasaddfnlem 16801 initoid 17265 termoid 17266 0subm 17982 smndex1mgm 18072 smndex1n0mnd 18077 grpinvfval 18142 0subg 18304 0nsg 18321 sylow2alem2 18743 gsumval3 19027 gsumzaddlem 19041 kerf1ghm 19497 kerf1hrmOLD 19498 lsssn0 19719 r0cld 22346 alexsubALTlem2 22656 tgphaus 22725 isusp 22870 i1f1lem 24290 ig1pcl 24769 plyco0 24782 plyeq0lem 24800 plycj 24867 wilthlem2 25646 dchrfi 25831 snstriedgval 26823 incistruhgr 26864 1loopgrnb0 27284 umgr2v2enb1 27308 usgr2pthlem 27544 hsn0elch 29025 h1de2ctlem 29332 atomli 30159 brsnop 30429 1stpreimas 30441 gsummpt2d 30687 kerunit 30896 qqhval2lem 31222 qqhf 31227 qqhre 31261 esum2dlem 31351 eulerpartlemb 31626 bnj149 32147 subfacp1lem6 32432 ellimits 33371 bj-0nel1 34268 bj-isrvec 34578 poimirlem18 34925 poimirlem21 34928 poimirlem22 34929 poimirlem31 34938 poimirlem32 34939 itg2addnclem2 34959 ftc1anclem3 34984 0idl 35318 keridl 35325 smprngopr 35345 isdmn3 35367 ellkr 36240 diblss 38321 dihmeetlem4preN 38457 dihmeetlem13N 38470 0prjspnrel 39289 pw2f1ocnv 39654 fvnonrel 39977 snhesn 40152 unirnmapsn 41497 sge0fodjrnlem 42718 lindslinindsimp1 44532 |
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