Theorem opeluu 4379

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. (Contributed by NM, 31-Mar-1995.) (Revised by Mario Carneiro, 27-Feb-2016.)

Hypotheses

Ref	Expression
opeluu.1	|- A e. _V
opeluu.2	|- B e. _V

Assertion

Ref	Expression
opeluu	|- ( <. A , B >. e. C -> ( A e. U. U. C /\ B e. U. U. C ) )

Proof of Theorem opeluu

Step	Hyp	Ref	Expression
1		opeluu.1	. . . 4 |- A e. _V
2	1	prid1 3637	. . 3 |- A e. { A , B }
3		opeluu.2	. . . . 5 |- B e. _V
4	1, 3	opi2 4163	. . . 4 |- { A , B } e. <. A , B >.
5		elunii 3749	. . . 4 |- ( ( { A , B } e. <. A , B >. /\ <. A , B >. e. C ) -> { A , B } e. U. C )
6	4, 5	mpan 421	. . 3 |- ( <. A , B >. e. C -> { A , B } e. U. C )
7		elunii 3749	. . 3 |- ( ( A e. { A , B } /\ { A , B } e. U. C ) -> A e. U. U. C )
8	2, 6, 7	sylancr 411	. 2 |- ( <. A , B >. e. C -> A e. U. U. C )
9	3	prid2 3638	. . 3 |- B e. { A , B }
10		elunii 3749	. . 3 |- ( ( B e. { A , B } /\ { A , B } e. U. C ) -> B e. U. U. C )
11	9, 6, 10	sylancr 411	. 2 |- ( <. A , B >. e. C -> B e. U. U. C )
12	8, 11	jca 304	1 |- ( <. A , B >. e. C -> ( A e. U. U. C /\ B e. U. U. C ) )

Syntax hints:   -> wi 4   /\ wa 103   e. wcel 1481   _Vcvv 2689   {cpr 3533   <.cop 3535   U.cuni 3744

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 699  ax-5 1424  ax-7 1425  ax-gen 1426  ax-ie1 1470  ax-ie2 1471  ax-8 1483  ax-10 1484  ax-11 1485  ax-i12 1486  ax-bndl 1487  ax-4 1488  ax-14 1493  ax-17 1507  ax-i9 1511  ax-ial 1515  ax-i5r 1516  ax-ext 2122  ax-sep 4054  ax-pr 4139

This theorem depends on definitions:  df-bi 116  df-3an 965  df-tru 1335  df-nf 1438  df-sb 1737  df-clab 2127  df-cleq 2133  df-clel 2136  df-nfc 2271  df-v 2691  df-un 3080  df-sn 3538  df-pr 3539  df-op 3541  df-uni 3745

This theorem is referenced by:  asymref  4932