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Mirrors > Home > MPE Home > Th. List > eqss | Structured version Visualization version GIF version |
Description: The subclass relationship is antisymmetric. Compare Theorem 4 of [Suppes] p. 22. (Contributed by NM, 21-May-1993.) |
Ref | Expression |
---|---|
eqss | ⊢ (𝐴 = 𝐵 ↔ (𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐴)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | albiim 1893 | . 2 ⊢ (∀𝑥(𝑥 ∈ 𝐴 ↔ 𝑥 ∈ 𝐵) ↔ (∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ∈ 𝐵) ∧ ∀𝑥(𝑥 ∈ 𝐵 → 𝑥 ∈ 𝐴))) | |
2 | dfcleq 2726 | . 2 ⊢ (𝐴 = 𝐵 ↔ ∀𝑥(𝑥 ∈ 𝐴 ↔ 𝑥 ∈ 𝐵)) | |
3 | dfss2 3969 | . . 3 ⊢ (𝐴 ⊆ 𝐵 ↔ ∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ∈ 𝐵)) | |
4 | dfss2 3969 | . . 3 ⊢ (𝐵 ⊆ 𝐴 ↔ ∀𝑥(𝑥 ∈ 𝐵 → 𝑥 ∈ 𝐴)) | |
5 | 3, 4 | anbi12i 628 | . 2 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐴) ↔ (∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ∈ 𝐵) ∧ ∀𝑥(𝑥 ∈ 𝐵 → 𝑥 ∈ 𝐴))) |
6 | 1, 2, 5 | 3bitr4i 303 | 1 ⊢ (𝐴 = 𝐵 ↔ (𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐴)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 205 ∧ wa 397 ∀wal 1540 = wceq 1542 ∈ wcel 2107 ⊆ wss 3949 |
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 |
This theorem is referenced by: eqssi 3999 eqssd 4000 sssseq 4001 sseq1 4008 sseq2 4009 ssrabeq 4083 dfpss3 4087 compleq 4148 uneqin 4279 rcompleq 4296 pssdifn0 4366 ss0b 4398 vss 4444 pwpw0 4817 sssn 4830 ssunsn 4832 pwsnOLD 4902 unidif 4947 ssunieq 4948 uniintsn 4992 iuneq1 5014 iuneq2 5017 iunxdif2 5057 ssext 5455 pweqb 5457 eqopab2bw 5549 eqopab2b 5553 pwun 5573 soeq2 5611 eqrel 5785 eqrelrel 5798 coeq1 5858 coeq2 5859 cnveq 5874 dmeq 5904 relssres 6023 xp11 6175 ssrnres 6178 ordtri4 6402 oneqmini 6417 fnres 6678 eqfnfv3 7035 fneqeql2 7049 dff3 7102 fconst4 7216 f1imaeq 7264 eqoprab2bw 7479 eqoprab2b 7480 iunpw 7758 orduniorsuc 7818 tfi 7842 fo1stres 8001 fo2ndres 8002 wfrlem8OLD 8316 tz7.49 8445 oawordeulem 8554 nnacan 8628 nnmcan 8634 ixpeq2 8905 sbthlem3 9085 isinf 9260 isinfOLD 9261 ordunifi 9293 inficl 9420 rankr1c 9816 rankc1 9865 iscard 9970 iscard2 9971 carden2 9982 aleph11 10079 cardaleph 10084 alephinit 10090 dfac12a 10143 cflm 10245 cfslb2n 10263 dfacfin7 10394 wrdeq 14486 isumltss 15794 rpnnen2lem12 16168 isprm2 16619 mrcidb2 17562 smndex2dnrinv 18796 iscyggen2 19749 iscyg3 19754 lssle0 20560 islpir2 20889 iscss2 21239 ishil2 21274 bastop1 22496 epttop 22512 iscld4 22569 0ntr 22575 opnneiid 22630 isperf2 22656 cnntr 22779 ist1-3 22853 perfcls 22869 cmpfi 22912 isconn2 22918 dfconn2 22923 snfil 23368 filconn 23387 ufileu 23423 alexsubALTlem4 23554 metequiv 24018 eqscut2 27307 nbuhgr2vtx1edgblem 28608 iscplgr 28672 shlesb1i 30639 shle0 30695 orthin 30699 chcon2i 30717 chcon3i 30719 chlejb1i 30729 chabs2 30770 h1datomi 30834 cmbr4i 30854 osumcor2i 30897 pjjsi 30953 pjin2i 31446 stcltr2i 31528 mdbr2 31549 dmdbr2 31556 mdsl2i 31575 mdsl2bi 31576 mdslmd3i 31585 chrelat4i 31626 sumdmdlem2 31672 dmdbr5ati 31675 eqdif 31757 eqrelrd2 31845 rspsnasso 32492 dfon2lem9 34763 idsset 34862 fneval 35237 topdifinfeq 36231 equivtotbnd 36646 heiborlem10 36688 eqrel2 37168 relcnveq3 37190 relcnveq2 37192 cossssid 37337 elrelscnveq3 37361 elrelscnveq2 37363 pmap11 38633 dia11N 39919 dia2dimlem5 39939 dib11N 40031 dih11 40136 dihglblem6 40211 doch11 40244 mapd11 40510 mapdcnv11N 40530 sticksstones11 40972 isnacs2 41444 mrefg3 41446 onsupneqmaxlim0 41973 onsupnmax 41977 ontric3g 42273 rababg 42325 relnonrel 42338 uneqsn 42776 ntrk1k3eqk13 42801 ntrneineine1lem 42835 ntrneicls00 42840 ntrneixb 42846 ntrneik13 42849 ntrneix13 42850 joindm2 47601 meetdm2 47603 |
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