Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
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 3112 | . 2 ⊢ (𝐴 = 𝐵 ↔ (𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐴)) | |
2 | sstr2 3104 | . . . 4 ⊢ (𝐵 ⊆ 𝐴 → (𝐴 ⊆ 𝐶 → 𝐵 ⊆ 𝐶)) | |
3 | 2 | adantl 275 | . . 3 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐴) → (𝐴 ⊆ 𝐶 → 𝐵 ⊆ 𝐶)) |
4 | sstr2 3104 | . . . 4 ⊢ (𝐴 ⊆ 𝐵 → (𝐵 ⊆ 𝐶 → 𝐴 ⊆ 𝐶)) | |
5 | 4 | adantr 274 | . . 3 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐴) → (𝐵 ⊆ 𝐶 → 𝐴 ⊆ 𝐶)) |
6 | 3, 5 | impbid 128 | . 2 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐴) → (𝐴 ⊆ 𝐶 ↔ 𝐵 ⊆ 𝐶)) |
7 | 1, 6 | sylbi 120 | 1 ⊢ (𝐴 = 𝐵 → (𝐴 ⊆ 𝐶 ↔ 𝐵 ⊆ 𝐶)) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 103 ↔ wb 104 = wceq 1331 ⊆ wss 3071 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-5 1423 ax-7 1424 ax-gen 1425 ax-ie1 1469 ax-ie2 1470 ax-8 1482 ax-11 1484 ax-4 1487 ax-17 1506 ax-i9 1510 ax-ial 1514 ax-i5r 1515 ax-ext 2121 |
This theorem depends on definitions: df-bi 116 df-nf 1437 df-sb 1736 df-clab 2126 df-cleq 2132 df-clel 2135 df-in 3077 df-ss 3084 |
This theorem is referenced by: sseq12 3122 sseq1i 3123 sseq1d 3126 nssne2 3156 sbss 3471 pwjust 3511 elpw 3516 elpwg 3518 sssnr 3680 ssprr 3683 sstpr 3684 unimax 3770 trss 4035 elssabg 4073 bnd2 4097 exmidexmid 4120 exmidsssn 4125 exmidsssnc 4126 mss 4148 exss 4149 frforeq2 4267 ordtri2orexmid 4438 ontr2exmid 4440 onsucsssucexmid 4442 reg2exmidlema 4449 sucprcreg 4464 ordtri2or2exmid 4486 onintexmid 4487 tfis 4497 tfisi 4501 elnn 4519 nnregexmid 4534 releq 4621 xpsspw 4651 iss 4865 relcnvtr 5058 iotass 5105 fununi 5191 funcnvuni 5192 funimaexglem 5206 ffoss 5399 ssimaex 5482 tfrlem1 6205 nnsucsssuc 6388 qsss 6488 phpm 6759 ssfiexmid 6770 findcard2d 6785 findcard2sd 6786 diffifi 6788 isinfinf 6791 fiintim 6817 fisseneq 6820 fidcenumlemrk 6842 fidcenumlemr 6843 sbthlem2 6846 isbth 6855 ctssdclemr 6997 elinp 7282 sup3exmid 8715 zfz1isolem1 10583 zfz1iso 10584 fimaxre2 10998 sumeq1 11124 fsum2d 11204 fsumabs 11234 fsumiun 11246 prodeq1f 11321 exmidunben 11939 ctiunct 11953 restsspw 12130 uniopn 12168 fiinopn 12171 fiinbas 12216 baspartn 12217 eltg2 12222 eltg3 12226 topbas 12236 clsval 12280 neival 12312 neiint 12314 neipsm 12323 opnneissb 12324 opnssneib 12325 innei 12332 restbasg 12337 cnpdis 12411 txbas 12427 eltx 12428 neitx 12437 txlm 12448 blssexps 12598 blssex 12599 neibl 12660 metrest 12675 xmettx 12679 tgioo 12715 tgqioo 12716 limcimolemlt 12802 recnprss 12825 bj-om 13135 bj-2inf 13136 bj-nntrans 13149 bj-omtrans 13154 el2oss1o 13188 exmid1stab 13195 subctctexmid 13196 |
Copyright terms: Public domain | W3C validator |