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| Mirrors > Home > NFE Home > Th. List > uni1ex | Unicode version | ||
| Description: The unit union operator preserves sethood. (Contributed by SF, 14-Jan-2015.) | 
| Ref | Expression | 
|---|---|
| uni1ex.1 | 
 | 
| Ref | Expression | 
|---|---|
| uni1ex | 
 | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | uni1ex.1 | 
. 2
 | |
| 2 | uni1exg 4293 | 
. 2
 | |
| 3 | 1, 2 | ax-mp 5 | 
1
 | 
| Colors of variables: wff setvar class | 
| Syntax hints:     | 
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1546 ax-5 1557 ax-17 1616 ax-9 1654 ax-8 1675 ax-6 1729 ax-7 1734 ax-11 1746 ax-12 1925 ax-ext 2334 ax-nin 4079 ax-xp 4080 ax-cnv 4081 ax-typlower 4087 ax-sn 4088 | 
| This theorem depends on definitions: df-bi 177 df-or 359 df-an 360 df-3an 936 df-nan 1288 df-tru 1319 df-ex 1542 df-nf 1545 df-sb 1649 df-clab 2340 df-cleq 2346 df-clel 2349 df-nfc 2479 df-ne 2519 df-ral 2620 df-rex 2621 df-v 2862 df-nin 3212 df-compl 3213 df-in 3214 df-un 3215 df-dif 3216 df-ss 3260 df-nul 3552 df-sn 3742 df-pr 3743 df-uni 3893 df-opk 4059 df-1c 4137 df-uni1 4139 df-xpk 4186 df-cnvk 4187 df-p6 4192 | 
| This theorem is referenced by: ncfinraiselem2 4481 nnpweqlem1 4523 sfintfinlem1 4532 tfinnnlem1 4534 vfinspclt 4553 1stex 4740 ssetex 4745 enpw1lem1 6062 nenpw1pwlem1 6085 nmembers1lem1 6269 nchoicelem16 6305 nchoicelem18 6307 | 
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