Theorem opeluu 4428

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 3682	. . 3 |- A e. { A , B }
3		opeluu.2	. . . . 5 |- B e. _V
4	1, 3	opi2 4211	. . . 4 |- { A , B } e. <. A , B >.
5		elunii 3794	. . . 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 3794	. . 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 3683	. . 3 |- B e. { A , B }
10		elunii 3794	. . 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 2136   _Vcvv 2726   {cpr 3577   <.cop 3579   U.cuni 3789

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 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-14 2139  ax-ext 2147  ax-sep 4100  ax-pr 4187

This theorem depends on definitions:  df-bi 116  df-3an 970  df-tru 1346  df-nf 1449  df-sb 1751  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-v 2728  df-un 3120  df-sn 3582  df-pr 3583  df-op 3585  df-uni 3790

This theorem is referenced by:  asymref  4989