![]() |
Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > n0i | Structured version Visualization version GIF version |
Description: If a class has elements, then it is not empty. (Contributed by NM, 31-Dec-1993.) |
Ref | Expression |
---|---|
n0i | ⊢ (𝐵 ∈ 𝐴 → ¬ 𝐴 = ∅) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | noel 4343 | . . 3 ⊢ ¬ 𝐵 ∈ ∅ | |
2 | eleq2 2827 | . . 3 ⊢ (𝐴 = ∅ → (𝐵 ∈ 𝐴 ↔ 𝐵 ∈ ∅)) | |
3 | 1, 2 | mtbiri 327 | . 2 ⊢ (𝐴 = ∅ → ¬ 𝐵 ∈ 𝐴) |
4 | 3 | con2i 139 | 1 ⊢ (𝐵 ∈ 𝐴 → ¬ 𝐴 = ∅) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 = wceq 1536 ∈ wcel 2105 ∅c0 4338 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1791 ax-4 1805 ax-5 1907 ax-6 1964 ax-7 2004 ax-8 2107 ax-9 2115 ax-ext 2705 |
This theorem depends on definitions: df-bi 207 df-an 396 df-tru 1539 df-fal 1549 df-ex 1776 df-sb 2062 df-clab 2712 df-cleq 2726 df-clel 2813 df-dif 3965 df-nul 4339 |
This theorem is referenced by: ne0i 4346 n0ii 4348 oprcl 4903 disjss3 5146 elfvdm 6943 mptrcl 7024 isomin 7356 ovrcl 7471 elfvov1 7472 elfvov2 7473 oalimcl 8596 omlimcl 8614 nnaordex2 8675 oaabs2 8685 ecexr 8748 elpmi 8884 elmapex 8886 pmresg 8908 pmsspw 8915 ixpssmap2g 8965 ixpssmapg 8966 resixpfo 8974 php3 9246 php3OLD 9258 cantnfp1lem2 9716 cantnflem1 9726 cnfcom2lem 9738 rankxplim2 9917 rankxplim3 9918 cardlim 10009 alephnbtwn 10108 ttukeylem5 10550 r1wunlim 10774 ssnn0fi 14022 ruclem13 16274 ramtub 17045 elbasfv 17250 elbasov 17251 restsspw 17477 homarcl 18081 grpidval 18686 odlem2 19571 efgrelexlema 19781 subcmn 19869 dvdsrval 20377 elocv 21703 pf1rcl 22368 matrcl 22431 0top 23005 ppttop 23029 pptbas 23030 restrcl 23180 ssrest 23199 iscnp2 23262 lmmo 23403 zfbas 23919 rnelfmlem 23975 isfcls 24032 isnghm 24759 iscau2 25324 itg2cnlem1 25810 itgsubstlem 26103 dchrrcl 27298 clwwlknnn 30061 0ringsubrg 33237 ssdifidllem 33463 ssmxidllem 33480 eulerpartlemgvv 34357 indispconn 35218 cvmtop1 35244 cvmtop2 35245 mrsub0 35500 mrsubf 35501 mrsubccat 35502 mrsubcn 35503 mrsubco 35505 mrsubvrs 35506 msubf 35516 mclsrcl 35545 funpartlem 35923 tailfb 36359 nlpineqsn 37390 atbase 39270 llnbase 39491 lplnbase 39516 lvolbase 39560 osumcllem4N 39941 pexmidlem1N 39952 lhpbase 39980 mapco2g 42701 wepwsolem 43030 onov0suclim 43263 uneqsn 44014 ssfiunibd 45259 hoicvr 46503 0nelsetpreimafv 47314 |
Copyright terms: Public domain | W3C validator |