Theorem abexex 6271

Description: A condition where a class builder continues to exist after its wff is existentially quantified. (Contributed by NM, 4-Mar-2007.)

Hypotheses

Ref	Expression
abexex.1	|- A e. _V
abexex.2	|- ( ph -> x e. A )
abexex.3	|- { y | ph } e. _V

Assertion

Ref	Expression
abexex	|- { y | E. x ph } e. _V

Distinct variable group:   x, y, A

Allowed substitution hints:   ph( x, y)

Proof of Theorem abexex

Step	Hyp	Ref	Expression
1		df-rex 2514	. . . 4 |- ( E. x e. A ph <-> E. x ( x e. A /\ ph ) )
2		abexex.2	. . . . . 6 |- ( ph -> x e. A )
3	2	pm4.71ri 392	. . . . 5 |- ( ph <-> ( x e. A /\ ph ) )
4	3	exbii 1651	. . . 4 |- ( E. x ph <-> E. x ( x e. A /\ ph ) )
5	1, 4	bitr4i 187	. . 3 |- ( E. x e. A ph <-> E. x ph )
6	5	abbii 2345	. 2 |- { y | E. x e. A ph } = { y | E. x ph }
7		abexex.1	. . 3 |- A e. _V
8		abexex.3	. . 3 |- { y | ph } e. _V
9	7, 8	abrexex2 6269	. 2 |- { y | E. x e. A ph } e. _V
10	6, 9	eqeltrri 2303	1 |- { y | E. x ph } e. _V

Syntax hints:   -> wi 4   /\ wa 104   E.wex 1538   e. wcel 2200   {cab 2215   E.wrex 2509   _Vcvv 2799

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 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-13 2202  ax-14 2203  ax-ext 2211  ax-coll 4199  ax-sep 4202  ax-pow 4258  ax-pr 4293  ax-un 4524

This theorem depends on definitions:  df-bi 117  df-3an 1004  df-tru 1398  df-nf 1507  df-sb 1809  df-eu 2080  df-mo 2081  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ral 2513  df-rex 2514  df-reu 2515  df-rab 2517  df-v 2801  df-sbc 3029  df-csb 3125  df-un 3201  df-in 3203  df-ss 3210  df-pw 3651  df-sn 3672  df-pr 3673  df-op 3675  df-uni 3889  df-iun 3967  df-br 4084  df-opab 4146  df-mpt 4147  df-id 4384  df-xp 4725  df-rel 4726  df-cnv 4727  df-co 4728  df-dm 4729  df-rn 4730  df-res 4731  df-ima 4732  df-iota 5278  df-fun 5320  df-fn 5321  df-f 5322  df-f1 5323  df-fo 5324  df-f1o 5325  df-fv 5326

This theorem is referenced by: (None)