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Mirrors > Home > MPE Home > Th. List > rexcom4 | Structured version Visualization version GIF version |
Description: Commutation of restricted and unrestricted existential quantifiers. (Contributed by NM, 12-Apr-2004.) (Proof shortened by Andrew Salmon, 8-Jun-2011.) Reduce axiom dependencies. (Revised by BJ, 13-Jun-2019.) |
Ref | Expression |
---|---|
rexcom4 | ⊢ (∃𝑥 ∈ 𝐴 ∃𝑦𝜑 ↔ ∃𝑦∃𝑥 ∈ 𝐴 𝜑) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-rex 3146 | . 2 ⊢ (∃𝑥 ∈ 𝐴 ∃𝑦𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ ∃𝑦𝜑)) | |
2 | 19.42v 1954 | . . . . 5 ⊢ (∃𝑦(𝑥 ∈ 𝐴 ∧ 𝜑) ↔ (𝑥 ∈ 𝐴 ∧ ∃𝑦𝜑)) | |
3 | 2 | bicomi 226 | . . . 4 ⊢ ((𝑥 ∈ 𝐴 ∧ ∃𝑦𝜑) ↔ ∃𝑦(𝑥 ∈ 𝐴 ∧ 𝜑)) |
4 | 3 | exbii 1848 | . . 3 ⊢ (∃𝑥(𝑥 ∈ 𝐴 ∧ ∃𝑦𝜑) ↔ ∃𝑥∃𝑦(𝑥 ∈ 𝐴 ∧ 𝜑)) |
5 | excom 2169 | . . . 4 ⊢ (∃𝑥∃𝑦(𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∃𝑦∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)) | |
6 | df-rex 3146 | . . . . . 6 ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)) | |
7 | 6 | bicomi 226 | . . . . 5 ⊢ (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∃𝑥 ∈ 𝐴 𝜑) |
8 | 7 | exbii 1848 | . . . 4 ⊢ (∃𝑦∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∃𝑦∃𝑥 ∈ 𝐴 𝜑) |
9 | 5, 8 | bitri 277 | . . 3 ⊢ (∃𝑥∃𝑦(𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∃𝑦∃𝑥 ∈ 𝐴 𝜑) |
10 | 4, 9 | bitri 277 | . 2 ⊢ (∃𝑥(𝑥 ∈ 𝐴 ∧ ∃𝑦𝜑) ↔ ∃𝑦∃𝑥 ∈ 𝐴 𝜑) |
11 | 1, 10 | bitri 277 | 1 ⊢ (∃𝑥 ∈ 𝐴 ∃𝑦𝜑 ↔ ∃𝑦∃𝑥 ∈ 𝐴 𝜑) |
Colors of variables: wff setvar class |
Syntax hints: ↔ wb 208 ∧ wa 398 ∃wex 1780 ∈ wcel 2114 ∃wrex 3141 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-11 2161 |
This theorem depends on definitions: df-bi 209 df-an 399 df-ex 1781 df-rex 3146 |
This theorem is referenced by: 2ex2rexrot 3252 rexcom4a 3253 rexcom 3357 reuind 3746 uni0b 4866 iuncom4 4929 dfiun2g 4957 dfiun2gOLD 4958 iunn0 4991 iunxiun 5021 iinexg 5246 inuni 5248 iunopab 5448 xpiundi 5624 xpiundir 5625 cnvuni 5759 dmiun 5784 dmopab2rex 5788 elsnres 5894 rniun 6008 xpdifid 6027 imaco 6106 coiun 6111 abrexco 7005 imaiun 7006 fliftf 7070 fiun 7646 f1iun 7647 oprabrexex2 7681 releldm2 7744 oarec 8190 omeu 8213 eroveu 8394 dfac5lem2 9552 genpass 10433 supaddc 11610 supadd 11611 supmul1 11612 supmullem2 11614 supmul 11615 pceu 16185 4sqlem12 16294 mreiincl 16869 psgneu 18636 ntreq0 21687 unisngl 22137 metrest 23136 metuel2 23177 istrkg2ld 26248 fpwrelmapffslem 30470 omssubaddlem 31559 omssubadd 31560 bnj906 32204 satfdm 32618 dmopab3rexdif 32654 nosupno 33205 nosupfv 33208 bj-elsngl 34282 bj-restn0 34383 ismblfin 34935 itg2addnclem3 34947 sdclem1 35020 eldmqs1cossres 35895 prter2 36019 lshpsmreu 36247 islpln5 36673 islvol5 36717 cdlemftr3 37703 mapdpglem3 38813 hdmapglem7a 39065 diophrex 39379 imaiun1 40003 coiun1 40004 grumnudlem 40628 upbdrech 41579 |
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