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Mirrors > Home > ILE Home > Th. List > elun | GIF version |
Description: Expansion of membership in class union. Theorem 12 of [Suppes] p. 25. (Contributed by NM, 7-Aug-1994.) |
Ref | Expression |
---|---|
elun | ⊢ (𝐴 ∈ (𝐵 ∪ 𝐶) ↔ (𝐴 ∈ 𝐵 ∨ 𝐴 ∈ 𝐶)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elex 2749 | . 2 ⊢ (𝐴 ∈ (𝐵 ∪ 𝐶) → 𝐴 ∈ V) | |
2 | elex 2749 | . . 3 ⊢ (𝐴 ∈ 𝐵 → 𝐴 ∈ V) | |
3 | elex 2749 | . . 3 ⊢ (𝐴 ∈ 𝐶 → 𝐴 ∈ V) | |
4 | 2, 3 | jaoi 716 | . 2 ⊢ ((𝐴 ∈ 𝐵 ∨ 𝐴 ∈ 𝐶) → 𝐴 ∈ V) |
5 | eleq1 2240 | . . . 4 ⊢ (𝑥 = 𝐴 → (𝑥 ∈ 𝐵 ↔ 𝐴 ∈ 𝐵)) | |
6 | eleq1 2240 | . . . 4 ⊢ (𝑥 = 𝐴 → (𝑥 ∈ 𝐶 ↔ 𝐴 ∈ 𝐶)) | |
7 | 5, 6 | orbi12d 793 | . . 3 ⊢ (𝑥 = 𝐴 → ((𝑥 ∈ 𝐵 ∨ 𝑥 ∈ 𝐶) ↔ (𝐴 ∈ 𝐵 ∨ 𝐴 ∈ 𝐶))) |
8 | df-un 3134 | . . 3 ⊢ (𝐵 ∪ 𝐶) = {𝑥 ∣ (𝑥 ∈ 𝐵 ∨ 𝑥 ∈ 𝐶)} | |
9 | 7, 8 | elab2g 2885 | . 2 ⊢ (𝐴 ∈ V → (𝐴 ∈ (𝐵 ∪ 𝐶) ↔ (𝐴 ∈ 𝐵 ∨ 𝐴 ∈ 𝐶))) |
10 | 1, 4, 9 | pm5.21nii 704 | 1 ⊢ (𝐴 ∈ (𝐵 ∪ 𝐶) ↔ (𝐴 ∈ 𝐵 ∨ 𝐴 ∈ 𝐶)) |
Colors of variables: wff set class |
Syntax hints: ↔ wb 105 ∨ wo 708 = wceq 1353 ∈ wcel 2148 Vcvv 2738 ∪ cun 3128 |
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-io 709 ax-5 1447 ax-7 1448 ax-gen 1449 ax-ie1 1493 ax-ie2 1494 ax-8 1504 ax-10 1505 ax-11 1506 ax-i12 1507 ax-bndl 1509 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-tru 1356 df-nf 1461 df-sb 1763 df-clab 2164 df-cleq 2170 df-clel 2173 df-nfc 2308 df-v 2740 df-un 3134 |
This theorem is referenced by: uneqri 3278 uncom 3280 uneq1 3283 unass 3293 ssun1 3299 unss1 3305 ssequn1 3306 unss 3310 rexun 3316 ralunb 3317 unssdif 3371 unssin 3375 inssun 3376 indi 3383 undi 3384 difundi 3388 difindiss 3390 undif3ss 3397 symdifxor 3402 rabun2 3415 reuun2 3419 undif4 3486 ssundifim 3507 dcun 3534 dfpr2 3612 eltpg 3638 pwprss 3806 pwtpss 3807 uniun 3829 intun 3876 iunun 3966 iunxun 3967 iinuniss 3970 brun 4055 undifexmid 4194 exmidundif 4207 exmidundifim 4208 exmid1stab 4209 pwunss 4284 elsuci 4404 elsucg 4405 elsuc2g 4406 ordsucim 4500 sucprcreg 4549 opthprc 4678 xpundi 4683 xpundir 4684 funun 5261 mptun 5348 unpreima 5642 reldmtpos 6254 dftpos4 6264 tpostpos 6265 onunsnss 6916 unfidisj 6921 undifdcss 6922 fidcenumlemrks 6952 djulclb 7054 eldju 7067 eldju2ndl 7071 eldju2ndr 7072 ctssdccl 7110 pw1nel3 7230 sucpw1nel3 7232 elnn0 9178 un0addcl 9209 un0mulcl 9210 elxnn0 9241 ltxr 9775 elxr 9776 fzsplit2 10050 elfzp1 10072 uzsplit 10092 elfzp12 10099 fz01or 10111 fzosplit 10177 fzouzsplit 10179 elfzonlteqm1 10210 fzosplitsni 10235 hashinfuni 10757 hashennnuni 10759 hashunlem 10784 zfz1isolemiso 10819 summodclem3 11388 fsumsplit 11415 fsumsplitsn 11418 sumsplitdc 11440 fprodsplitdc 11604 fprodsplit 11605 fprodunsn 11612 fprodsplitsn 11641 nnnn0modprm0 12255 prm23lt5 12263 reopnap 14041 lgsdir2 14437 2lgsoddprmlem3 14462 djulclALT 14556 djurclALT 14557 bj-charfun 14562 bj-nntrans 14706 bj-nnelirr 14708 |
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