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| Mirrors > Home > ILE Home > Th. List > abrexex2 | GIF version | ||
| Description: Existence of an existentially restricted class abstraction. 𝜑 is normally has free-variable parameters 𝑥 and 𝑦. See also abrexex 6174. (Contributed by NM, 12-Sep-2004.) | 
| Ref | Expression | 
|---|---|
| abrexex2.1 | ⊢ 𝐴 ∈ V | 
| abrexex2.2 | ⊢ {𝑦 ∣ 𝜑} ∈ V | 
| Ref | Expression | 
|---|---|
| abrexex2 | ⊢ {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝜑} ∈ V | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | nfv 1542 | . . . 4 ⊢ Ⅎ𝑧∃𝑥 ∈ 𝐴 𝜑 | |
| 2 | nfcv 2339 | . . . . 5 ⊢ Ⅎ𝑦𝐴 | |
| 3 | nfs1v 1958 | . . . . 5 ⊢ Ⅎ𝑦[𝑧 / 𝑦]𝜑 | |
| 4 | 2, 3 | nfrexw 2536 | . . . 4 ⊢ Ⅎ𝑦∃𝑥 ∈ 𝐴 [𝑧 / 𝑦]𝜑 | 
| 5 | sbequ12 1785 | . . . . 5 ⊢ (𝑦 = 𝑧 → (𝜑 ↔ [𝑧 / 𝑦]𝜑)) | |
| 6 | 5 | rexbidv 2498 | . . . 4 ⊢ (𝑦 = 𝑧 → (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥 ∈ 𝐴 [𝑧 / 𝑦]𝜑)) | 
| 7 | 1, 4, 6 | cbvab 2320 | . . 3 ⊢ {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝜑} = {𝑧 ∣ ∃𝑥 ∈ 𝐴 [𝑧 / 𝑦]𝜑} | 
| 8 | df-clab 2183 | . . . . 5 ⊢ (𝑧 ∈ {𝑦 ∣ 𝜑} ↔ [𝑧 / 𝑦]𝜑) | |
| 9 | 8 | rexbii 2504 | . . . 4 ⊢ (∃𝑥 ∈ 𝐴 𝑧 ∈ {𝑦 ∣ 𝜑} ↔ ∃𝑥 ∈ 𝐴 [𝑧 / 𝑦]𝜑) | 
| 10 | 9 | abbii 2312 | . . 3 ⊢ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 ∈ {𝑦 ∣ 𝜑}} = {𝑧 ∣ ∃𝑥 ∈ 𝐴 [𝑧 / 𝑦]𝜑} | 
| 11 | 7, 10 | eqtr4i 2220 | . 2 ⊢ {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝜑} = {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 ∈ {𝑦 ∣ 𝜑}} | 
| 12 | df-iun 3918 | . . 3 ⊢ ∪ 𝑥 ∈ 𝐴 {𝑦 ∣ 𝜑} = {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 ∈ {𝑦 ∣ 𝜑}} | |
| 13 | abrexex2.1 | . . . 4 ⊢ 𝐴 ∈ V | |
| 14 | abrexex2.2 | . . . 4 ⊢ {𝑦 ∣ 𝜑} ∈ V | |
| 15 | 13, 14 | iunex 6180 | . . 3 ⊢ ∪ 𝑥 ∈ 𝐴 {𝑦 ∣ 𝜑} ∈ V | 
| 16 | 12, 15 | eqeltrri 2270 | . 2 ⊢ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 ∈ {𝑦 ∣ 𝜑}} ∈ V | 
| 17 | 11, 16 | eqeltri 2269 | 1 ⊢ {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝜑} ∈ V | 
| Colors of variables: wff set class | 
| Syntax hints: [wsb 1776 ∈ wcel 2167 {cab 2182 ∃wrex 2476 Vcvv 2763 ∪ ciun 3916 | 
| 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 710 ax-5 1461 ax-7 1462 ax-gen 1463 ax-ie1 1507 ax-ie2 1508 ax-8 1518 ax-10 1519 ax-11 1520 ax-i12 1521 ax-bndl 1523 ax-4 1524 ax-17 1540 ax-i9 1544 ax-ial 1548 ax-i5r 1549 ax-13 2169 ax-14 2170 ax-ext 2178 ax-coll 4148 ax-sep 4151 ax-pow 4207 ax-pr 4242 ax-un 4468 | 
| This theorem depends on definitions: df-bi 117 df-3an 982 df-tru 1367 df-nf 1475 df-sb 1777 df-eu 2048 df-mo 2049 df-clab 2183 df-cleq 2189 df-clel 2192 df-nfc 2328 df-ral 2480 df-rex 2481 df-reu 2482 df-rab 2484 df-v 2765 df-sbc 2990 df-csb 3085 df-un 3161 df-in 3163 df-ss 3170 df-pw 3607 df-sn 3628 df-pr 3629 df-op 3631 df-uni 3840 df-iun 3918 df-br 4034 df-opab 4095 df-mpt 4096 df-id 4328 df-xp 4669 df-rel 4670 df-cnv 4671 df-co 4672 df-dm 4673 df-rn 4674 df-res 4675 df-ima 4676 df-iota 5219 df-fun 5260 df-fn 5261 df-f 5262 df-f1 5263 df-fo 5264 df-f1o 5265 df-fv 5266 | 
| This theorem is referenced by: abexssex 6182 abexex 6183 oprabrexex2 6187 ab2rexex 6188 ab2rexex2 6189 | 
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