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Mirrors > Home > ILE Home > Th. List > sseq1 | GIF version |
Description: Equality theorem for subclasses. (Contributed by NM, 5-Aug-1993.) (Proof shortened by Andrew Salmon, 21-Jun-2011.) |
Ref | Expression |
---|---|
sseq1 | ⊢ (𝐴 = 𝐵 → (𝐴 ⊆ 𝐶 ↔ 𝐵 ⊆ 𝐶)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqss 3170 | . 2 ⊢ (𝐴 = 𝐵 ↔ (𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐴)) | |
2 | sstr2 3162 | . . . 4 ⊢ (𝐵 ⊆ 𝐴 → (𝐴 ⊆ 𝐶 → 𝐵 ⊆ 𝐶)) | |
3 | 2 | adantl 277 | . . 3 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐴) → (𝐴 ⊆ 𝐶 → 𝐵 ⊆ 𝐶)) |
4 | sstr2 3162 | . . . 4 ⊢ (𝐴 ⊆ 𝐵 → (𝐵 ⊆ 𝐶 → 𝐴 ⊆ 𝐶)) | |
5 | 4 | adantr 276 | . . 3 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐴) → (𝐵 ⊆ 𝐶 → 𝐴 ⊆ 𝐶)) |
6 | 3, 5 | impbid 129 | . 2 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐴) → (𝐴 ⊆ 𝐶 ↔ 𝐵 ⊆ 𝐶)) |
7 | 1, 6 | sylbi 121 | 1 ⊢ (𝐴 = 𝐵 → (𝐴 ⊆ 𝐶 ↔ 𝐵 ⊆ 𝐶)) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 104 ↔ wb 105 = wceq 1353 ⊆ wss 3129 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-5 1447 ax-7 1448 ax-gen 1449 ax-ie1 1493 ax-ie2 1494 ax-8 1504 ax-11 1506 ax-4 1510 ax-17 1526 ax-i9 1530 ax-ial 1534 ax-i5r 1535 ax-ext 2159 |
This theorem depends on definitions: df-bi 117 df-nf 1461 df-sb 1763 df-clab 2164 df-cleq 2170 df-clel 2173 df-in 3135 df-ss 3142 |
This theorem is referenced by: sseq12 3180 sseq1i 3181 sseq1d 3184 nssne2 3214 sbss 3531 pwjust 3576 elpw 3581 elpwg 3583 sssnr 3753 ssprr 3756 sstpr 3757 unimax 3843 trss 4110 elssabg 4148 bnd2 4173 exmidexmid 4196 exmidsssn 4202 exmidsssnc 4203 exmid1stab 4208 mss 4226 exss 4227 frforeq2 4345 ordtri2orexmid 4522 ontr2exmid 4524 onsucsssucexmid 4526 reg2exmidlema 4533 sucprcreg 4548 ordtri2or2exmid 4570 ontri2orexmidim 4571 onintexmid 4572 tfis 4582 tfisi 4586 elomssom 4604 nnregexmid 4620 releq 4708 xpsspw 4738 iss 4953 relcnvtr 5148 iotass 5195 fununi 5284 funcnvuni 5285 funimaexglem 5299 ffoss 5493 ssimaex 5577 tfrlem1 6308 el2oss1o 6443 nnsucsssuc 6492 qsss 6593 phpm 6864 ssfiexmid 6875 findcard2d 6890 findcard2sd 6891 diffifi 6893 isinfinf 6896 fiintim 6927 fisseneq 6930 fidcenumlemrk 6952 fidcenumlemr 6953 sbthlem2 6956 isbth 6965 ctssdclemr 7110 onntri45 7239 tapeq1 7250 elinp 7472 sup3exmid 8913 zfz1isolem1 10819 zfz1iso 10820 fimaxre2 11234 sumeq1 11362 fsum2d 11442 fsumabs 11472 fsumiun 11484 prodeq1f 11559 fprod2d 11630 exmidunben 12426 ctiunct 12440 ssomct 12445 restsspw 12697 uniopn 13471 fiinopn 13474 fiinbas 13519 baspartn 13520 eltg2 13523 eltg3 13527 topbas 13537 clsval 13581 neival 13613 neiint 13615 neipsm 13624 opnneissb 13625 opnssneib 13626 innei 13633 restbasg 13638 cnpdis 13712 txbas 13728 eltx 13729 neitx 13738 txlm 13749 blssexps 13899 blssex 13900 neibl 13961 metrest 13976 xmettx 13980 tgioo 14016 tgqioo 14017 limcimolemlt 14103 recnprss 14126 bj-om 14659 bj-2inf 14660 bj-nntrans 14673 bj-omtrans 14678 subctctexmid 14720 pw1nct 14722 |
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