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| Description: Each member of an ordered pair belongs to the union of the union of a class to which the ordered pair belongs. Lemma 3D of [Enderton] p. 41. |
| Ref | Expression |
|---|---|
| opeluu |
|
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elunii 3182 |
. . 3
| |
| 2 | visset 2295 |
. . . 4
| |
| 3 | 2 | prid1 3106 |
. . 3
|
| 4 | opi2 3530 |
. . . 4
| |
| 5 | elunii 3182 |
. . . 4
| |
| 6 | 4, 5 | mpan 759 |
. . 3
|
| 7 | 1, 3, 6 | sylancr 526 |
. 2
|
| 8 | elunii 3182 |
. . 3
| |
| 9 | visset 2295 |
. . . 4
| |
| 10 | 9 | prid2 3107 |
. . 3
|
| 11 | 8, 10, 6 | sylancr 526 |
. 2
|
| 12 | 7, 11 | jca 310 |
1
|
| Colors of variables: wff set class |
| Syntax hints: |
| This theorem is referenced by: asymref 4308 asymref2 4310 |
| This theorem was proved from axioms: ax-1 4 ax-2 5 ax-3 6 ax-mp 7 ax-7 1304 ax-gen 1305 ax-8 1306 ax-9 1307 ax-10 1308 ax-11 1309 ax-12 1310 ax-14 1312 ax-17 1317 ax-4 1319 ax-5o 1321 ax-6o 1324 ax-9o 1481 ax-10o 1500 ax-16 1580 ax-11o 1588 ax-ext 1865 ax-sep 3438 ax-nul 3445 ax-pow 3481 ax-pr 3524 |
| This theorem depends on definitions: df-bi 164 df-or 241 df-an 242 df-ex 1327 df-sb 1536 df-clab 1872 df-cleq 1877 df-clel 1880 df-ne 2019 df-v 2294 df-dif 2597 df-un 2600 df-in 2603 df-ss 2605 df-nul 2876 df-pw 3035 df-sn 3049 df-pr 3050 df-op 3053 df-uni 3178 |