Theorem bj-inex 16847

Description: The intersection of two sets is a set, from bounded separation. (Contributed by BJ, 19-Nov-2019.) (Proof modification is discouraged.)

Assertion

Ref	Expression
bj-inex	|- ( ( A e. V /\ B e. W ) -> ( A i^i B ) e. _V )

Proof of Theorem bj-inex

Dummy variables x y z are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		elisset 2836	. 2 |- ( A e. V -> E. x x = A )
2		elisset 2836	. 2 |- ( B e. W -> E. y y = B )
3		ax-17 1579	. . . 4 |- ( E. y y = B -> A. x E. y y = B )
4		19.29r 1674	. . . 4 |- ( ( E. x x = A /\ A. x E. y y = B ) -> E. x ( x = A /\ E. y y = B ) )
5	3, 4	sylan2 286	. . 3 |- ( ( E. x x = A /\ E. y y = B ) -> E. x ( x = A /\ E. y y = B ) )
6		ax-17 1579	. . . . 5 |- ( x = A -> A. y x = A )
7		19.29 1673	. . . . 5 |- ( ( A. y x = A /\ E. y y = B ) -> E. y ( x = A /\ y = B ) )
8	6, 7	sylan 283	. . . 4 |- ( ( x = A /\ E. y y = B ) -> E. y ( x = A /\ y = B ) )
9	8	eximi 1653	. . 3 |- ( E. x ( x = A /\ E. y y = B ) -> E. x E. y ( x = A /\ y = B ) )
10		ineq12 3427	. . . . 5 |- ( ( x = A /\ y = B ) -> ( x i^i y ) = ( A i^i B ) )
11	10	2eximi 1654	. . . 4 |- ( E. x E. y ( x = A /\ y = B ) -> E. x E. y ( x i^i y ) = ( A i^i B ) )
12		dfin5 3227	. . . . . . 7 |- ( x i^i y ) = { z e. x | z e. y }
13		vex 2824	. . . . . . . 8 |- x e. _V
14		ax-bdel 16761	. . . . . . . . 9 |- BOUNDED z e. y
15		bdcv 16788	. . . . . . . . 9 |- BOUNDED x
16	14, 15	bdrabexg 16846	. . . . . . . 8 |- ( x e. _V -> { z e. x | z e. y } e. _V )
17	13, 16	ax-mp 5	. . . . . . 7 |- { z e. x | z e. y } e. _V
18	12, 17	eqeltri 2311	. . . . . 6 |- ( x i^i y ) e. _V
19		eleq1 2301	. . . . . 6 |- ( ( x i^i y ) = ( A i^i B ) -> ( ( x i^i y ) e. _V <-> ( A i^i B ) e. _V ) )
20	18, 19	mpbii 148	. . . . 5 |- ( ( x i^i y ) = ( A i^i B ) -> ( A i^i B ) e. _V )
21	20	exlimivv 1952	. . . 4 |- ( E. x E. y ( x i^i y ) = ( A i^i B ) -> ( A i^i B ) e. _V )
22	11, 21	syl 14	. . 3 |- ( E. x E. y ( x = A /\ y = B ) -> ( A i^i B ) e. _V )
23	5, 9, 22	3syl 17	. 2 |- ( ( E. x x = A /\ E. y y = B ) -> ( A i^i B ) e. _V )
24	1, 2, 23	syl2an 289	1 |- ( ( A e. V /\ B e. W ) -> ( A i^i B ) e. _V )

Syntax hints:   -> wi 4   /\ wa 104   A.wal 1400   = wceq 1402   E.wex 1545   e. wcel 2209   {crab 2532   _Vcvv 2821   i^i cin 3219

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220  ax-bd0 16753  ax-bdan 16755  ax-bdel 16761  ax-bdsb 16762  ax-bdsep 16824

This theorem depends on definitions:  df-bi 117  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-rab 2537  df-v 2823  df-in 3226  df-ss 3233  df-bdc 16781

This theorem is referenced by:  speano5  16884